The 100 most-cited articles in Inorganic Chemistry, 2022

The origin and assignment of the complex main and satellite X-ray photoelectron spectroscopy (XPS) features of the cations in ionic compounds have been the subject of extensive theoretical studies using different methods. There is agreement that within a molecular orbital model, one needs to take into account different types of configurations. Specifically, those where a core electron is removed, but no other configuration changes are made and those where in addition to ionization, there are also shake or charge-transfer changes to the ionic configuration. However, there are strong disagreements about the assignment of XPS features to these configurations. The present work is directed toward resolving the origin of main and satellite features for the Ni 2p XPS of NiO based on ab initio molecular orbital wave functions (WFs) for a cluster model of NiO. A major problem in earlier ab initio XPS studies of ionic compounds has been the use of a common set of orbitals that was not able to properly describe all the ionic configurations that contribute to the full XPS spectra. This is…

The synthesis of five- and six-membered oxygen- and nitrogen-containing heterocycles has been regarded as the most fundamental issue in organic chemistry and chemical industry because they are used in producing high-value products. In this study, an efficient, economic, sustainable, and green protocol for multicomponent synthesis has been developed. The one-pot direct Knoevenagel condensation–Michael addition–cyclization sequences for the transformation of aromatic aldehydes, malononitrile, and 4-hydroxycoumarin or phthalhydrazide generate the corresponding dihydropyrano[2,3- c ]chromenes and 1 H -pyrazolo[1,2- b ]phthalazine-5,10-diones over a novel mesoporous metal–organic framework-based supported Cu(II) nanocatalyst [UiO-66@Schiff-Base-Cu(II)] under ambient conditions. Moreover, the [UiO-66@Schiff-Base-Cu(II)] complex efficiently catalyzed the selectively large-scale synthesis of the target molecules with high yield and large turnover numbers. As presented, the catalyst demonstrates excellent reusability and stability and can be recycled up to six runs without noticeable loss of…

Due to the increasing environmental pollution caused by human activities, environmental remediation has become an important subject for humans and environmental safety. The quest for beneficial pathways to remove organic and inorganic contaminants has been the theme of considerable investigations in the past decade. The easy and quick separation made magnetic solid-phase extraction (MSPE) a popular method for the removal of different pollutants from the environment. Metal–organic frameworks (MOFs) are a class of porous materials best known for their ultrahigh porosity. Moreover, these materials can be easily modified with useful ligands and form various composites with varying characteristics, thus rendering them an ideal candidate as adsorbing agents for MSPE. Herein, research on MSPE, encompassing MOFs as sorbents and Fe 3 O 4 as a magnetic component, is surveyed for environmental applications. Initially, assorted pollutants and their threats to human and environmental safety are introduced with a brief introduction to MOFs and MSPE. Subsequently, the deployment of magnetic MOFs…

The design and preparation of novel multifunctional lanthanide metal–organic frameworks (Ln-MOFs) have been arisen widespread attention. In particular, Ln-MOFs have shown great luminescence potential in chemical sensing. Herein, a new benzothiadiazole-based Eu-MOF {[(CH 3 ) 2 NH 2 ][Eu(BTDB) 2 ]·2H 2 O} n ( JXUST-11 ) was obtained based on 4,4′-(benzo[ c ][1,2,5]thiadiazole-4,7-diyl)dibenzoic acid (H 2 BTDB), which exhibits a chain-based three-dimensional framework. Moreover, JXUST-11 is considered as a photoluminescent sensor to identify Al 3+ and Ga 3+ ions by fluorescence enhancement with the detection limits of 2.9 and 10.2 ppm, severally. Importantly, Al 3+ and Ga 3+ can be discerned with the naked eye by color change under a natural lamp. In addition, a portable MOF film based on JXUST-11 was developed for Al 3+ and Ga 3+ detection. This is the first Ln-MOF that can be employed as a naked-eye fluorescent probe to identify Ga 3+ . Interestingly, JXUST-11 is also capable of detecting Al 3+ and Ga 3+ in living cells.

Compared to freshwater electrolysis, seawater electrolysis to produce hydrogen is preferable and more promising, but this technology is plagued by the electrode’s corrosion and oxidative reactions of the competitive Cl – ion on the anode. To develop efficient oxygen evolution reaction (OER) catalysts for seawater electrolysis, the ultrathin MnO x film-covered NiFe-layered double-hydroxide nanosheet array is directly assembled on Ni foam (MnO x /NiFe-LDH/NF) by hydrothermal and electrodeposition in turn. This catalyst demonstrates excellent OER-selective activity in alkaline saline electrolytes. In 1 M KOH/0.5 M NaCl and 1 M KOH/seawater electrolytes, MnO x /NiFe-LDH/NF exhibits lower overpotentials at 100 mA cm –2 (η 100 values of 265 and 276 mV, respectively) and Tafel slopes (73 and 77 mV decade –1, respectively) than does the NiFe-LDH/NF electrode (η 100 values of 298 and 327 mV and Tafel slopes of 91 and 140 mV decade –1, respectively). In alkaline saline solutions, the stability and durability of the former are also better than those of the latter. The good OER selectivity and…

Rational design and construction of well-defined hollow heterostructured nanomaterials assembled by ultrathin nanosheets overtakes crucial role in developing high-efficiency oxygen evolution reaction (OER) electrocatalysts. Herein, a reliable metal–organic framework-mediated and cation-exchange strategy to tune the geometric structure and multicomponent heterostructures has been proposed for the fabrication of hollow CoWO 4 –Co(OH) 2 hierarchical nanoboxes assembled by rich ultrathin nanosheets. Benefiting from the hierarchical hollow nanostructure, the CoWO 4 –Co(OH) 2 nanoboxes offer plenty of metal active centers available for reaction intermediates. Moreover, the well-defined nanointerfaces between CoWO 4 and Co(OH) 2 can function as the bridge for boosting the efficient electron transfer from CoWO 4 to Co(OH) 2 . As a consequence, the optimized CoWO 4 –Co(OH) 2 nanoboxes can exhibit outstanding electrocatalytic performance toward OER by delivering 10 mA cm –2 with a low overpotential of 280 mV and a small Tafel slope of 70.6 mV dec –1 as well as outstanding electrochemical…

The electrooxidation of ethylene glycol (EG) is of vital significance for the conversion from biomass energy into electrical energy via direct fuel cells. However, the EG oxidation reaction (EGOR) suffers from poor efficiency due to the limitation of high-performance electrocatalysts for cleaving the C–C bonds. Herein, this limitation is successfully addressed by fabricating the doughnut-shaped Pd–Bi 2 Te 3 heterostructured catalyst. Notably, the heterojunction Pd–Bi 2 Te 3 nanocatalyst has been demonstrated to be highly active toward the EGOR with superb activity and durability, in which a mass activity as high as 2420.8 mA mg –1 is achieved in alkaline media, being 1.7 times higher than that of the commercial Pd/C catalyst. Upon combination of experimental results with mechanism studies, it is indicated that the remarkable EGOR performance is attributed to the enlarged active areas that stemmed from the doughnut-like structure, as well as the strong synergistic effect from Pd–Bi 2 Te 3 and Pd. More importantly, the highly electroactive Pd–Bi 2 Te 3 can accelerate charge transfer…

The rapid detection of antibiotics in agricultural products is of great significance. In this work, two stable fluorescent metal-organic frameworks (MOFs), BUT-178 and BUT-179, are synthesized and used to detect tetracycline antibiotics. Among them, BUT-179 exhibits better performance in the detection of different tetracycline antibiotics in water and eggs. The limits of detection of BUT-179 toward tetracycline, aureomycin, oxytetracycline, and doxycycline all reach the nanomolar level. Furthermore, the cycling tests confirm that BUT-179 can be easily recovered and repeatedly used without an obvious performance loss. This work demonstrates the excellent application potential of MOFs for food safety, especially the fluorescence detection of antibiotics in foods.

It is a challenge to fabricate atomically dispersed metal clusters in polymeric carbon nitride (PCN) for durable photocatalytic reactions owing to the thermodynamic stability limitation. Herein, atomically dispersed Ru clusters are implanted into the PCN skeleton matrix based on an ionic diffusion and coordination (IDC) strategy, the stability of which is improved owing to the robust Ru–N bonds in the formed RuN 4 and RuN 3 configurations. Additionally, RuN 4 and RuN 3 as charge transport bridges between two adjacent melon strands efficaciously conquer hydrogen bond restriction in the skeleton to facilitate the in-plane mobility and separation of charge carriers. Moreover, the synergistic effect of adjacent Ru atoms is triggered on the assembled RuN 3 –RuN 4 and RuN 3 –RuN 3 in the atomically dispersed Ru clusters to significantly decrease hydrogen adsorption energy. As a result, the optimal PCN-Ru photocatalyst achieves nearly 6 times higher than the photocatalytic hydrogen evolution (PHE) rate of the Pt/PCN benchmark and maintains the long-term stable running for 104 h of 26…

As a novel electrode material for energy storage, metal–organic frameworks (MOFs) emerge with plenty of merits and certain drawbacks in the field of supercapacitors. Nevertheless, most MOFs synthesized for the moment are faced with dimension/distribution issues and dissatisfactory electrical conductivity. Hence, in this paper, NiCo-MOF was successfully fabricated by applying a one-step solvothermal method, from which NiCo-MOF-3 presents an optimal electrochemical performance compared to other NiCo-MOFs and Ni/Co-MOF. Owing to its unique three-dimensional spherical raspberry structure, NiCo-MOF-3 demonstrates an available internal resistance and electron transfer resistance to ameliorate electrical energy storage, exhibiting an excellent mass specific capacitance of 639.8 F/g at 1 A/g. Then, a flexible quasi-solid-state asymmetric supercapacitor was assembled with NiCo-MOF-3 as the positive electrode. The introduction of K 3 [Fe(CN) 6 ] and glycerin in the gel electrolyte facilitates the maximum energy density of 66.3 Wh/kg of the device, with a corresponding power density reaching…

Trivalent metal ions (Cr 3+, Al 3+, and Fe 3+ ) constitute a major section of the environmental pollutants, and their excess accumulation has a detrimental effect on health, so their detection in trace quantity has been a hot topic of research. A highly scalable 3D porous Zn-based luminescent metal–organic framework (MOF) has been synthesized by exploiting the mixed ligand synthesis concept. The strategic selection of an aromatic π-conjugated organic linker and N-rich spacer containing the azine functionality as metal ion binding sites immobilized across the pore spaces, have made this MOF an ideal turn-on sensor for Al 3+, Cr 3+, and Fe 3+ ions with very high sensitivity, selectivity, and recyclability. An in-depth study revealed absorbance caused enhancement mechanism (ACE) responsible for such turn-on phenomena. In order to make the detection process straightforward, convenient, portable, and economically viable, we have fabricated MOF test paper strips (the MOF could be simply immobilized onto the paper strips) for naked eye visual detection under UV light, which, thus,…

The development of cost-effective and efficient oxygen evolution reaction (OER) catalysts has found increasing popularity due to the sluggish kinetics of OER, which has hampered the H 2 production by H 2 O electrolysis. In this study, Fe 2 Ni MIL-88 (denoted FeNi) was composited by reduced graphene oxide (rGO, denoted R). Owing to the high porosity and abundant active sites of bimetallic MOF, proper conductivity of rGO, and the synergistic impact of Ni and Fe, the optimal composite (R@FeNi (1:1)) offered remarkable OER activity in alkaline environments. The obtained composite was employed in the OER, which led to a low overpotential of 264 mV at a current density of 10 mA cm –2 with a Tafel slope of 62 mV dec –1 . Also, the bimetallic Fe 2 Ni MIL-88 nanorods grown on rGO led to a reduction in the onset potential of the OER. These findings exceeded the results of standard IrO 2 -based catalysts; they are also comparable or even better than the previously reported MOF-based catalysts.

Oxygen evolution reaction (OER) represents a highly important electrochemical transformation in energy storage and conversion technologies. Considering the low rate of this four-electron half-reaction, there is a demand for efficient, stable, and noble-metal-free electrocatalysts to improve the kinetic and economical parameters. In this work, a new [email protected] nanocomposite based on a Co II metal–organic framework (pillared-MOF) and heterometallic Ni/V-layered double hydroxide (NiV-LDH) was assembled via a simple protocol, characterized, and explored as an electrocatalyst in OER. A remarkable electrocatalytic efficiency of [email protected] in 1 M KOH is evidenced by a low overpotential (238 mV at 10 mA cm –2 current density) and a small value of the Tafel slope (62 mV dec –1 ). These parameters are very close to those of the reference IrO 2 electrocatalyst and are superior to the majority of the LDH- and MOF-based systems previously applied for OER. Excellent stability of [email protected] was confirmed by the chronopotentiometry tests for 70 h and linear-sweep voltammetry…

Vast attention from researchers is being given to the development of suitable oxygen evolution reaction (OER) electrocatalysts via water electrolysis. Being highly abundant, the use of transition-metal-based OER catalysts has been attractive more recently. Among the various transition-metal-based electrocatalysts, the use of layered double hydroxides (LDHs) has gained special attention from researchers owing to their high stability under OER conditions. In this work, we have reported the synthesis of trimetallic NiCoV-LDH via a simple wet-chemical method. The synthesized NiCoV-LDH possesses aggregated sheet-like structures and is screened for OER studies in alkaline medium. In the study of OER activity, the as-prepared catalyst demanded 280 mV overpotential and this was 42 mV less than the overpotential essential for pristine NiCo-LDH. Moreover, doping of a third metal into the NiCo-LDH system might lead to an increase in TOF values by almost three times. Apart from this, the electronic structural evaluation confirms that the doping of V 3+ into NiCo-LDH could synergistically favor…

Trivalent europium-based monochromatic red light-emitting phosphors are an essential component to realize high-performance smart lighting devices; however, the concentration and thermal quenching restrict their usage. Here, we report a series of efficient Eu 3+ -substituted Li 3 Y 3 BaSr(MoO 4 ) 8 red-emitting phosphors based on a stratified scheelite structure with negligible concentration and thermal quenching. All of the host and phosphor compositions crystallize in monoclinic crystal structure (space group C 2/ c ). All of the phosphor compositions produce narrow-band red emission (FWHM ∼6 nm), which is highly apparent to the human eyes, and lead to exceptional chromatic saturation of the red spectral window. Concurrently, detailed investigations were carried out to comprehend the concentration and thermal quenching mechanism. Absolute quantum yields as high as 88.5% were obtained for Li 3 Y 0.3 Eu 2.7 BaSr(MoO 4 ) 8 phosphor with virtuous thermal stability (at 400 K, retaining 87% of its emission intensity). The light-emitting diodes were constructed by coupling Li 3 BaSrY 0.3…

The rational design of a two-dimensional (2D)/2D “face-to-face” heterojunction photocatalyst is crucial for the mediation of interfacial charge transfer/separation. Herein, a unique 2D/2D step-scheme (S-scheme) photocatalyst of CsPbBr 3 /BiOCl is constructed by the self-assembly of CsPbBr 3 and BiOCl nanosheets (NSs). Profiting from the effective interface contact and appropriate band structures between CsPbBr 3 and BiOCl NSs, a valid S-scheme heterojunction of CsPbBr 3 /BiOCl is established. Density functional theory (DFT) calculations and a series of characterization techniques including X-ray photoelectron spectra (XPS), photoassisted Kelvin probe force microscopy (KPFM), and electron spin resonance (ESR) systematically corroborate the S-scheme charge-transfer mechanism between CsPbBr 3 and BiOCl. The formation of an S-scheme heterojunction endows the photocatalyst with boosted charge separation and retainment of the highest redox ability. As a result, the obtained 2D/2D CsPbBr 3 /BiOCl S-scheme photocatalyst shows much superior CO 2 -reduction performance to single CsPbBr 3 and…

Heterojunction manipulation has been deemed as a promising approach in exploring efficient photocatalysts for CO 2 reduction. In this article, a novel step-scheme (S-scheme) photocatalyst of CsPbBr 3 quantum dots/BiOBr nanosheets (CPB/BiOBr) was fabricated via a facile self-assembly process. The strong interaction, staggered energy band alignments, and much different Fermi levels between CsPbBr 3 and BiOBr promised the formation of an S-scheme heterojunction. The resultant CPB/BiOBr heterojunction delivered remarkable photocatalytic performance in CO 2 reduction, with an electron consumption rate of 72.3 μmol g –1 h –1, which was 4.1 and 5.7 times that of single CsPbBr 3 and BiOBr, respectively. The superior photocatalytic performance originated from the impactful spatial separation of photoinduced electron–hole pairs, as well as the preservation of strongly reductive electrons for CO 2 reduction. This work offers a rational strategy to design S-scheme heterojunctions based on lead halide perovskites, which are expected to have potential applications in the field of photocatalysis…

Herein, MOF-808 (MOF = metal–organic framework) based on zirconium tricarboxylate was synthesized to investigate the influence of decorating groups of folic acid-conjugated chitosan (CS-FA) on drug-delivery efficiency. Quercetin (QU) was loaded on nondecorated MOF-808 and then decorated with a folic acid–chitosan conjugate. The properties and activities of modified MOF-808 were compared with unmodified MOF-808. QU@MOF-808@CS-FA exhibited favorable drug-release properties, high drug-loading capacity, efficient targeting capability, and pH-dependent release behavior, highlighting the critical role of organic modification. A variety of characterization techniques were used to characterize MOF nanoparticles, including Fourier transform infrared, powder X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray, transmission electron microscopy, Brunauer–Emmett–Teller, ζ potential, and 1 H NMR. Additionally, Monte Carlo simulation calculations were carried out to examine the interactions between the structures of MOF-808 and QU. An in vitro cytotoxicity test…

The development of chemically stable metal–organic framework (MOF)-based luminescent platforms for toxic ion detection in an aqueous medium is highly challenging because most of the classical MOFs are prone to water degradation, and that is the reason why most of the MOF-based luminescent sensors use a nonaqueous medium for sensing. In this contribution, we report two new water-stable luminescent MOFs (Zn-MOF-1 and Zn-MOF-2), assembled from a mixed-ligand synthesis approach. Because of the presence of a hydrophobic trifluoromethyl group to the backbone and stronger metal–N coordination, these MOFs exhibit excellent stability not only in water but also in acidic/alkaline aqueous solutions (pH = 3–10). Here, we report a green sensing approach by exploiting the significant reduction in photoluminescence of these MOFs in the presence of toxic ions. Fe 3+ and CrO 4 2– /Cr 2 O 7 2– ions could be traced with a detection limit (LOD) in the micromolar range (0.045 and 0.745/0.33 μM for Zn-MOF-1; 125.2 and 114.2/83.5 μM for Zn-MOF-2). The mechanistic study reveals that competitive absorption…

A new polydentate tetracarboxylic acid with a benzothiadiazole unit (4′,4′′′-(benzo[ c ][1,2,5]thiadiazole-4,7-diyl)bis([1,1′-biphenyl]-3,5-dicarboxylic acid), H 4 BTDBA) has been used to prepare a pH-stable three-dimensional Tb III -based metal–organic framework (MOF) with the formula {[(CH 3 ) 2 NH 2 ] 0.7 [Tb 2 (BTDBA) 1.5 (lac) 0.7 (H 2 O) 2 ]·solvents} n (Hlac = lactic acid, JXUST-19 ). JXUST-19 exhibits a new (4,4,12)-connected topology based on tetranuclear [Tb 4 ] clusters. JXUST-19 can remain stable when soaked in water for at least 1 week and in aqueous solutions with various pH values (2–12) for 24 h. Fluorescence study indicates JXUST-19 can be employed as a rare turn-on and blue-shift MOF sensor toward benzaldehyde (BZ) and salicylaldehyde (SA). To date, JXUST-19 represents the first Tb III -based turn-on MOF sensor toward salicylaldehyde in aqueous solution, and the fluorescence enhancement and naked-eye detection of BZ have been rarely reported. In addition, JXUST-19 based fluorescent test papers, light-emitting diode lamp beads, and portable composite films were…

Four new isostructural lanthanide metal–organic frameworks (MOFs), namely {[Ln(DMTP-DC) 1.5 (H 2 O) 3 ]·DMF} n [H 2 DMTP-DC = 2′,5′-dimethoxytriphenyl-4,4″-dicarboxylic acid; Ln III = Eu III ( 1 ), Gd III ( 2 ), Tb III ( 3 ), and Dy III ( 4 )], have been synthesized and characterized. Single-crystal structure analysis reveals that 1 – 4 are three-dimensional Ln-MOFs with rich H-bonding of coordinated H 2 O molecules in the network channels. The X-ray diffraction patterns indicate that Ln-MOF 1 displays good stabilities in organic solvents and aqueous solutions with distinct pH values. Both 1 and 3 show characteristic emission of Ln III ions. Ln-MOF 1 can be used as a ratiometric fluorescence sensor for arginine and lysine in aqueous solution, and the detection limits are 24.38 μM for arginine and 9.31 μM for lysine. All 1 – 4 show proton conductivity related to relative humidity (RH) and temperature, and the maximum conductivity values of 1 – 4 at 55 °C and 100% RH are 9.94 × 10 –5, 1.62 × 10 –4, 1.71 × 10 –4, and 2.67 × 10 –4 S·cm –1, respectively. The value of σ increases with the…

The high catalytic activity of metal–organic frameworks (MOFs) can be realized by increasing their effective active sites, which prompts us to perform the functionalization on selected linkers by introducing a strong Lewis basic group of fluorine. Herein, the exquisite combination of paddle-wheel [Cu 2 (CO 2 ) 4 (H 2 O)] clusters and meticulously designed fluorine-funtionalized tetratopic 2′,3′-difluoro-[ p -terphenyl]-3,3″,5,5″-tetracarboxylic acid (F-H 4 ptta) engenders one peculiar nanocaged {Cu 2 }-organic framework of {[Cu 2 (F-ptta)(H 2 O) 2 ]·5DMF·2H 2 O} n ( NUC-54 ), which features two types of nanocaged voids (9.8 Å × 17.2 Å and 10.1 Å × 12.4 Å) shaped by 12 paddle-wheel [Cu 2 (COO) 4 H 2 O) 2 ] secondary building units, leaving a calculated solvent-accessible void volume of 60.6%. Because of the introduction of plentifully Lewis base sites of fluorine groups, activated NUC-54a exhibits excellent catalytic performance on the cycloaddition reaction of CO 2 with various epoxides under mild conditions. Moreover, to expand the catalytic scope, the deacetalization-Knoevenagel…

The design of white-light phosphor is highly desirable for practical applications in SSL (solid-state lighting) and its related fields. Dye-loaded metal-organic frameworks (MOFs) have been widely demonstrated as one type of promising down conversion materials for WLEDs (white-light-emitting diodes), but two issues (dye leakage and inadequate quantum efficiency) require to be addressed before possible applications. Here, a series of single-phase dyes@In-MOF phosphors have been prepared in two different ways: the in-situ process and soaking method. The study of these dyes@In-MOF phosphors confirms the importance of this in-situ process that could effectively increase dye loading and quantum efficiency and greatly decrease dye leakage. As a result, a perfect WLED, fabricated using the in-situ-synthesized (AF/RhB@In-MOF)-3 (AF: Acriflavine; RhB: Rhodamine B) and 450 nm blue LED chip, exhibited a very high quantum yield (QY, up to 42.27%), a high luminous efficacy (LE) of 50.75 lm/W, a high color rendering index (CRI) of 91.2, and nearly identical Commission International ed'Eclairage…

The development of supramolecular coordination complexes (SCCs) with a bright aggregate state or mechanical-stimuli-responsive luminescence is very significant and challenging. Herein, we report the synthesis of three different supramolecular platinum(II) metallacycles via coordination-driven self-assembly of a diplatinum(II) acceptor and organic donors with a triphenylamine, carbazole, or tetraphenylethylene moiety. The triphenylamine-modified SCC exhibits aggregation-induced emission enhancement (AIEE) but no mechanofluorochromism. The carbazole and tetraphenylethylene-based SCCs exhibit changes in aggregate fluorescence and also exhibit reversible mechanofluorochromism. This work not only reports three rare metallacycles with AIEE, aggregate fluorescence change, or mechanofluorochromic nature but also explores their potential applications in cell imaging and solid-state lighting.

Two-dimensional (2D) metal–organic framework (MOF) nanosheets have been demonstrated to be promising templates for the growth of various kinds of nanomaterials on their surfaces to construct novel 2D composites, thus realizing enhanced performance in various applications. Herein, we report the growth of Cu 2 O nanoparticles on 2D Zr–ferrocene (Zr-Fc)–MOF (Zr-Fc-MOF) nanosheets to prepare 2D composites for near-infrared (NIR) photothermally enhanced chemodynamic antibacterial therapy. The uniform Zr-Fc-MOF nanosheets are synthesized using the solvothermal method, followed by ultrasound sonication, and Cu 2 O nanoparticles are then deposited on its surface to obtain the Cu 2 O-decorated Zr-Fc-MOF (denoted as Cu 2 O/Zr-Fc-MOF) 2D composite. Promisingly, the Cu 2 O/Zr-Fc-MOF composite shows higher chemodynamic activity for producing ·OH via Fenton-like reaction than that of the pristine Zr-Fc-MOF nanosheets. More importantly, the chemodynamic activity of the Cu 2 O/Zr-Fc-MOF composite can be further enhanced by the photothermal effect though NIR laser (808 nm) irradiation. Thus, the Cu…

Light-driven splitting of water to produce H 2 and reduction of molecular oxygen to synthesize H 2 O 2 from water are the emerging environmentally friendly methods for converting solar energy into green energy and chemicals. In this paper, vacancy defect and heterojunction engineering effectively adjusted the conduction band position of Zn 3 In 2 S 6, enriched the electron density, broadened the optical absorption range, increased the specific surface area, and accelerated the charge carrier transfer and separation of g-C 3 N 4 /sulfur-vacancy-containing Zn 3 In 2 S 6 (CN/Vs-ZIS) heterostructures. As a result, all of the CN/Vs-ZIS heterostructures possessed greatly enhanced photocatalytic activities and the optimized sample 2CN/Vs-ZIS exhibited the highest visible-light photocatalytic performance. The rate of generation of H 2 of 2CN/Vs-ZIS under visible light (λ > 420 nm) was 6.55 mmol g –1 h –1, which was 1.76 and 6.06 times higher than those of Vs-Zn 3 In 2 S 6 and g-C 3 N 4, respectively, and the apparent quantum yield (AQY) was 18.6% at 420 nm. Meanwhile, the 2 h yield of H 2 O…

Nanoporous metal–organic frameworks (MOFs) have been gaining a reputation for their drug delivery applications. In the current work, MOF-801 was successfully prepared by a facile, cost-efficient, and environmentally friendly approach through the reaction of ZrCl 4 and fumaric acid as organic linkers to deliver 5-fluorouracil (5-FU). The prepared nanostructure was fully characterized by a series of analytical techniques including Fourier transform infrared spectroscopy, powder X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, UV–vis spectroscopy, 1 H NMR spectroscopy, thermogravimetric analysis, high-performance liquid chromatography, and Brunauer–Emmett–Teller analysis. MOF-801 could be used for the delivery of the anticancer drug 5-FU due to its high surface area, suitable pore size, and biocompatible ingredients. Based on in vitro loading and release studies, a high 5-FU loading capacity and pH-dependent drug release behavior were observed. Moreover, the interactions between the structure of MOFs and 5-FU were investigated…

High-entropy materials, with complex compositions and unique cocktail characteristics, have recently drawn significant attention. Additionally, a family of sodium super ion conductors (NASICONs)-structured phosphates in energy storage areas shows a comprehensive application for traditional alkaline ion batteries and, in particular, solid-state electrolytes. However, there is no precedent in fabricating this kind of NASICON-type high-entropy phase. Here, we report the successful fabrication of two well-crystallized high-entropy phosphates, namely, Na 3 (Ti 0.2 V 0.2 Mn 0.2 Cr 0.2 Zr 0.2 ) 2 (PO 4 ) 3 (HE-N 3 M 2 P 3 ) and Na(Ti 0.2 V 0.2 Mn 0.2 Cr 0.2 Zr 0.2 ) 2 PO 4 O x (HE-NMP). The prepared materials in which the transition metals (TMs) of Ti, V, Mn, Cr, and Zr occupy the same 12c Wykoff position can form a structure analogous to R 3̅ c Na 3 V 2 (PO 4 ) 3 that is carefully determined by X-ray diffraction, neutron diffraction, and transmission electron microscopy. Further, their performance for sodium ion batteries and sodium-based solid-state electrolytes was evaluated. The HE-N 3…

Controlling the structure of halide perovskites through component engineering, and thus revealing the changes in luminescence properties caused by the conversion of crystal structure, is of great significance. Herein, we report a controllable synthetic strategy of three-dimensional (3D) Cs 2 KInCl 6 and zero-dimensional (0D) (Cs/K) 2 InCl 5 (H 2 O) halide perovskites by changing the Cs/K feed ratio. 3D Cs 2 KInCl 6 double perovskites are obtained at the Cs/K feed ratio of 1:1, while 0D (Cs/K) 2 InCl 5 (H 2 O) perovskites are formed at the Cs/K feed ratio of 2:1. Further, a reversible crystal structure transformation between 3D Cs 2 KInCl 6 double perovskites and 0D (Cs/K) 2 InCl 5 (H 2 O) perovskites can be achieved by subsequent addition of metal-salt precursors. In addition, the emission efficiency of two perovskite structures can be greatly boosted by breaking the forbidden transition through Sb doping, and as a result, a novel green/yellow reversible emission switch is generated. Meanwhile, the relationship between perovskite structure and luminescence mechanism has been…

@NU-1000 nanocomposite for various optoelectronic purposes. This research may thus open new horizons to improve and enhance the NLO performance of MOF-based materials through π-electron delocalization and compositing metal-organic networks with inorganic molecules as electron acceptors, paving the way for the generation of novel types of hybrid materials for prospective NLO applications.

Broadband near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) are essential to integrate near-infrared spectrometers into mobile devices for the rapid and noninvasive detection of biological components. However, efficient broadband NIR phosphors with a peak emission wavelength longer than 800 nm are deficient. In this study, CaMgGe 2 O 6:Cr 3+ phosphor was prepared by a high-temperature solid-state reaction. The phosphor doped with 0.02Cr 3+ showed an emission band at 845 nm with a broad bandwidth of 160 nm and a high quantum yield of 84% under 450 nm excitation. The broadband NIR pc-LED was fabricated using CaMgGe 2 O 6:0.02Cr 3+ phosphor based on a blue light-emitting diode (LED) chip. A photoelectric efficiency of 27.2% @ 10 mA and an NIR output power of 57.98 mW @ 100 mA were achieved, which are the highest values reported yet for broadband NIR pc-LEDs with a peak wavelength longer than 800 nm. Using the fabricated NIR pc-LED as the light source, the characteristic absorption spectra of some substances were obtained. All of the results indicated that the…

Herein, UiO-66 and its two functional analogs (with −NO 2 and −NH 2 functional groups) were synthesized, and their potential ability as pH stimulus nanocarriers of quercetin (QU), an anticancer agent, was studied. UiO-66 is a low-toxicity, biocompatible metal–organic framework with a large surface area and good stability, which can be prepared through a facile and inexpensive method. Before and after drug loading, various analyses were conducted to characterize the synthesized nanocarriers. Moreover, Monte Carlo simulations were performed to investigate their structures and interactions with quercetin. The most promising drug loading potential and prolonged drug release (over 25 days) were observed in QU@UiO-66-NO 2 with 37% drug loading content, which was the best-tested sample that exhibited a higher release rate under acidic conditions (pH = 5) than that in normal cells (pH = 7.4). This behavior is known as pH-stimulus-controlled ability. The cell treatment with free QU, UiO-66-R, and QU@UiO-66-R (R = −H, −NO 2, and −NH 2 ) was performed, and an MTT assay was conducted on HEK-293…

Recently, stimuli-responsive materials have attracted great attention, while most of them respond to single or two stimuli. Thus, it is essential to design multifunctional stimuli-responsive materials and develop their applications. The strategy that constructing high-dimensional coordination polymers facilitates the application scope of a viologen-based photochromic system is put forward and confirmed for the first time. Herein, a novel multistimuli-responsive viologen-based Zn-MOF with a two-dimensional framework has been successfully designed and synthesized. Complex 1 exhibits chromic behavior under a variety of external stimuli such as 365 nm UV, X-rays, heat, electricity, and ethylamine. More interestingly, the crystal state of complex 1 displays dual fluorescence and room-temperature phosphorescence (RTP) emission and emits a yellow afterglow when turning off the UV lamp. In addition, Eu(III)-functionalized hybrids, Eu 3+ @Zn-MOF, were prepared by coordinated postsynthetic modification based on viologen complexes for the first time. The sample of Eu 3+ @Zn-MOF inherits the…

Three new polyoxometalate-based metal–organic frameworks (POMOFs) [Cu 4 (μ 3 - OH) 2 (tba) 3 (H 2 O) 5 (SiW 12 O 40 ) 0.5 ](H 2 SiW 12 O 40 ) 0.5 ·2.5H 2 O ( CuSiW ), [Cu 3 (μ 3 - OH)(tba) 3 (Htba)(H 2 O) 2 (HPMo 12 O 40 )]·7H 2 O ( CuPMo ), and [Cu 4 (μ 3 - OH) 2 (tba) 3 (H 2 O) 3 (PW 12 O 40 ) 0.5 ] 2 (PW 12 O 40 )·0.5H 2 O ( CuPW ) were constructed using multinuclear copper clusters, 3-(4 H -1,2,4-triazol-4-yl)benzoic acid (Htba), and Keggin polyoxometalates (POMs). Different POMs regulate the formation of different multinuclear copper clusters (“boat” tetranuclear clusters in CuSiW, trinuclear clusters in CuPMo, and “chair” tetranuclear clusters in CuPW ) and different topological structures of CuSiW, CuPMo, and CuPW (3-connected two-dimensional (2D) network for CuSiW, 4-connected 2D network for CuPMo, and (4,6)-connected three-dimensional network for CuPW ). CuSiW, CuPMo, and CuPW as heterogeneous catalysts combine the high stability of MOFs in polar solvents and excellent catalytic activity of POMs and could be used for the synthesis of nitrogen-heterocycle compounds. The…

High Resolution Image Download MS PowerPoint Slide Electrocatalytic generation of oxygen is of great significance for sustainable, clean, and efficient energy production. Multiple electron transfer in oxygen evolution reaction (OER) and its slow kinetics represent a serious hedge for efficient water splitting, requiring the design and development of advanced electrocatalysts with porous structures, high surface areas, abundant electroactive sites, and low overpotentials. These requisites are common for metal–organic frameworks (MOFs) and derived materials that are promising electrocatalysts for OER. The present work reports on the synthesis and full characterization of a heteroleptic 3D MOF, [Zn 2 (μ 4 -odba) 2 (μ-bpdh)] n · n DMF (Zn-MUM-1), assembled from 4,4′-oxydibenzoic acid and 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene (bpdh). Besides, a series of heterometallic MnZn-MUM-1 frameworks (abbreviated as Mn 0.5 Zn 0.5 -MUM-1, Mn 0.66 Zn 0.33 -MUM-1, and Mn 0.33 Zn 0.66 -MUM-1) was also prepared, characterized, and used for the fabrication of working electrodes based on Ni foam…

High Resolution Image Download MS PowerPoint Slide Magnetic bistability in single-molecule magnets (SMMs) is a potential basis for new types of nanoscale information storage material. The standard model for thermally activated relaxation of the magnetization in SMMs is based on the occurrence of a single Orbach process. Here, we show that incorporating a phosphorus atom into the framework of the dysprosium metallocene [(Cp i Pr5 )Dy(Cp PEt4 )] + [B(C 6 F 5 ) 4 ] − (Cp i Pr5 is penta-isopropylcyclopentadienyl, Cp PEt4 is tetraethylphospholyl) leads to the occurrence of two distinct high-temperature Orbach processes, with energy barriers of 1410(10) and 747(7) cm –1, respectively. These barriers provide experimental evidence for two different spin–phonon coupling regimes, which we explain with the aid of ab initio calculations. The strong and highly axial crystal field in this SMM also allows magnetic hysteresis to be observed up to 70 K, using a scan rate of 25 Oe s –1 . In characterizing this SMM, we show that a conventional Debye model and consideration of rotational contributions…

Due to their important role in biological systems, it is urgent to develop a material that can rapidly and sensitively detect the concentration of Fe 3+ and Al 3+ ions. In this work, a brand-new Cd II -based metal–organic framework [Cd(BTBD) 2 (AIC)] n ( JXUST-18, BTBD = 4,7-bis(1 H -1,2,4-triazol-1-yl)-2,1,3-benzothiadiazole and H 2 AIC = 5-aminoisophthalic acid) with a 4-connected sql topology was designed and synthesized. The symmetrical Cd II centers are linked by AIC 2– ligands with μ 3 -η 1:η 1:η 1:η 1 coordination mode to form a [Cd 2 (COO) 2 ] secondary building unit (SBU). The contiguous SBUs are further connected by BTBD ligands to form a two-dimensional (2D) layer structure. JXUST-18 can remain stable in aqueous solutions with pH values of 3–12 or in boiling water. Luminescent experiments suggest that JXUST-18 displays more than eightfold fluorescence enhancement in the presence of Fe 3+ and Al 3+ ions, and the detection limits for Fe 3+ and Al 3+ ions are 0.196 and 0.184 μM, respectively. Furthermore, the change in luminescence color is uncomplicatedly distinguishable…

To ameliorate the inherent thermal quenching behaviors of upconverting materials, a series of Ho 3+ /Yb 3+ -codoped Al 2 Mo 3 O 12 (i.e., Al 2 Mo 3 O 12:Ho 3+ /2 x Yb 3+ ) microparticles were developed. Upon excitation at 980 nm, intense upconversion (i.e., UC) emissions arising from Ho 3+ are observed, and their optimal states occur at x = 0.09. Besides, the UC mechanisms of these generated emissions from 5 F 4 / 5 S 2 and 5 F 5 levels all pertain to a two-photon absorption process. Furthermore, modified thermal quenching performances are realized in the resultant microparticles, in which the intensities of the UC emissions arising from 5 F 4 / 5 S 2 levels decrease as the temperature increases, while that of the UC emission from the 5 F 5 level increases and then decreases with the increase of temperature. The coexistence of nonradiative transition promoted crossrelaxation, and energy transfer routes can be responsible for the above phenomenon. By studying the diverse UC emission characteristics at high temperatures, we revealed the thermometric properties of Al 2 Mo 3 O 12:Ho 3+…

Nickel-based bimetallic oxides such as NiMoO 4 and NiWO 4, when deposited on the electrode substrate, show remarkable activity toward the electrocatalytic oxygen evolution reaction (OER). The stability of such nanostructures is nevertheless speculative, and catalytically active species have been less explored. Herein, NiMoO 4 nanorods and NiWO 4 nanoparticles are prepared via a solvothermal route and deposited on nickel foam (NF) (NiMoO 4 /NF and NiWO 4 /NF). After ensuring the chemical and structural integrity of the catalysts on electrodes, an OER study has been performed in the alkaline medium. After a few cyclic voltammetry (CV) cycles within the potential window of 1.0–1.9 V (vs reversible hydrogen electrode (RHE)), ex situ Raman analysis of the electrodes infers the formation of NiO(OH) ED (ED: electrochemically derived) from NiMoO 4 precatalyst, while NiWO 4 remains stable. A controlled study, stirring of NiMoO 4 /NF in 1 M KOH without applied potential, confirms that NiMoO 4 hydrolyzes to the isolable NiO, which under a potential bias converts into NiO(OH) ED . Perhaps the…

Tuning the electronic state of a nanocatalyst is of vital importance for elevating its catalytic performance toward oxygen evolution reaction (OER). Herein, a cation–anion dual doping strategy has been proposed for modifying the electronic structure of CoP via doping Fe and S atoms. Impressively, Fe doping has been demonstrated to be favorable for improving the carrier density of CoP to produce more hydroxyl radicals ( • OH), while S doping can further modify the electronic structure of CoP to improve the charge-transfer characteristics, thereby synergistically decreasing the energy barrier for the transformation of O* to OOH* and promoting the electrocatalytic OER performance. More importantly, the highly open nanobox structure is also beneficial for the exposure of more accessible catalytically active sites, which can substantially facilitate the electron and mass transport, leading to the superb catalytic OER performance. The successful modulation of OER performance via dual-doping strategy will pose a new strategy for designing more advanced nanocatalysts for energy-related…

Capturing volatile radionuclide iodine produced in the nuclear industry is a crucial environmental issue. In previous studies, the principal efficient adsorbent for iodine capture was silver-containing zeolite. As silver-containing zeolites are expensive, alternate copper-loaded porous zeolites, including CuCl loaded NaY reduced by H 2 (denoted as H 2 CuY) and CO (denoted as COCuY), were studied for iodine adsorption at moderate temperatures. The current work also discusses the influence of copper valency on iodine adsorption. Due to the copper sites and nanosized pore structure, H 2 CuY and COCuY showed high iodine adsorption capacities of 450 and 219 mg/g, respectively. The iodine adsorption capacity of H 2 CuY was higher than that of silver-loaded zeolites. Moreover, H 2 CuY and COCuY adsorbed volatile iodine through a chemical mechanism involving the copper sites of different valencies, and the Cu 0 was more effective in adsorbing iodine than Cu + . These copper-loaded zeolites with strong chemical interactions with iodine and high iodine adsorption capacities provided the…

By immobilizing the chiral center l -histidine ( l -His) into a Zr-based metal–organic framework (MOF) through post-synthetic ligand exchange, a chiral compound MOF-His has been prepared. On this basis, MOF-His is hybridized with Eu 3+ ions to obtain the final responsive compound Eu@MOF-His. It is worth noting that the bifunctional material exhibits enantioselective luminescence properties for tryptophan enantiomers. The experimental results demonstrate that tryptophan enantiomers can effectively quench the red-light emission of Eu 3+ ions, and also, the quenching rates are various, which may originate from the differences in the interaction between analytes and chiral recognition sites. In addition, Eu@MOF-His can realize the sensing of tryptophan enantiomers in serum. Concurrently, the compound possesses reusability, high sensitivity, and fast response speed, which means that it has the potential to serve as an excellent fluorescent sensor for detecting and identifying tryptophan enantiomers.

Bright red-emitting phosphors with high color purity and high photoluminescence quantum yield (PLQY) are highly demanded for the fabrication of high-performance warm-white light-emitting diodes (LEDs). Herein, we demonstrated a novel efficient Eu 3+ -activated Ca 2 LaHf 2 Al 3 O 12 garnet phosphor with excellent luminescence properties for near-ultraviolet (near-UV) excited warm-white LEDs. The Ca 2 LaHf 2 Al 3 O 12:Eu 3+ phosphors exhibited an intense excitation spectrum in the near-UV region with a maximum around 394 nm, and they produced dazzling red luminescence peaking at 592, 614, 659, and 711 nm due to the 5 D 0 → 7 F J ( J = 1–4) transitions of Eu 3+ ions when the excitation wavelength was set at 394 nm. Luminescent properties have been studied as a function of Eu 3+ doping concentration, and the highest emission intensity was achieved at 50 mol % Eu 3+, while the dipole–dipole interaction brought the concentration quenching effect. The Ca 2 LaHf 2 Al 3 O 12:50%Eu 3+ sample exhibited CIE chromaticity coordinates of (0.6419, 0.3575) with a color purity of 92.7%, and its PLQY…

A reasonable design of samples with efficient spatial separation for photoinduced electron–hole pairs toward the photocatalytic hydrogen evolution reaction (HER) has gained significant attention. Herein, a new C/MoS 2 @ZnIn 2 S 4 /Co 3 O 4 composite with a core–shell structure is designed toward photocatalytic hydrogen production on C/MoS 2 and Co 3 O 4 dual electron collectors. Co 3 O 4 nanoparticles as the co-catalyst would form a Schottky junction with ZnIn 2 S 4 nanosheets while the C/MoS 2 hollow core would form the step-scheme (S-scheme) heterojunction with ZnIn 2 S 4 sheets, which provides a dual photogenerated electron transfer pathway during the light irradiation process. In addition, the unique core–shell architecture offers large contact interfaces favoring the exposure of rich active sites, which facilitated the separation and the transfer of charges. Consequently, all these factors endowed the C/MoS 2 @ZnIn 2 S 4 /Co 3 O 4 composite with enhanced light absorption ability and an increased hydrogen evolution rate of 6.7 mmol·g –1 ·h –1 under 420 nm light irradiation,…

Photocatalytic CO 2 reduction to carbon fuels is regarded as an ideal and sustainable way to provide clean energy and solve environmental crisis. Herein, a p–n Co 3 O 4 /TiO 2 heterojunction photocatalyst was synthesized by one-step pyrolysis of self-assembly ZIF-67/MIL-125, which was used in photocatalytic CO 2 reduction for the first time. Co 3 O 4 nanocages were highly dispersed on the surface of TiO 2 nanoplates with an intimate contact. The optimal Co 3 O 4 /TiO 2 exhibited a significantly enhanced CO evolution rate of 1256 μmol g –1 h –1 under simulated solar light, which was 2.4 times higher than that of pure Co 3 O 4 . The high photocatalytic performance of Co 3 O 4 /TiO 2 was attributed to its enriched active sites and formed p–n heterojunctions. According to the electrocatalytic measurements, the possible mechanism and photoinduced charge transfer process were discussed in detail. We believe that this research provides a facile and efficient approach to fabricate MOF-derived heterojunction photocatalysts for CO 2 reduction.

Metal halide perovskites have flexible crystal and electronic structures and adjustable emission characteristics, which have very broad applications in the optoelectronic field. Among them, all-inorganic perovskites have attracted more attention than others in recent years because of their characteristics of large diffusion length, high luminescence efficiency, and good stability. In this work, Sb 3+ -doped RbCdCl 3 crystalline powder was synthesized by a simple hydrothermal method, and its luminescence properties were studied, which showed a broad emission band with a large Stokes shift and efficient yellow light emission at about 596 nm at room temperature with a photoluminescence quantum yield of 91.7%. The emission came from the transition of the self-trapped exciton 1 (STE1) out of 3 P n ( n = 0, 1, and 2) to S 0 due to strong electron–phonon coupling, which scaled with increasing temperature. Moreover, its emission color became white at low temperatures due to the occurrence of transition of other self-trapped exciton 0 (STE0) state emission out of the 1 S states of Sb ions to…

Nowadays, the construction of photothermal therapy (PTT) agents integrated with real-time thermometry for cancer treatment in deep tissues has become a research hotspot. Herein, an excellent photothermal conversion material, BaY 2 O 4: Yb 3+ /Nd 3+, assembled with real-time optical thermometry is developed successfully. Ultrasensitive temperature sensing is implemented through the fluorescence intensity ratio of thermally coupled Nd 3+: 4 F j ( j = 7/2, 5/2, and 3/2) with a maximal absolute and relative sensitivity of 68.88 and 3.29% K –1, respectively, which surpass the overwhelming majority of the same type of thermometers. Especially, a thermally enhanced Nd 3+ luminescence with a factor of 180 is detected with irradiation at 980 nm, resulting from the improvement in phonon-assisted energy transfer efficiency. Meanwhile, the photothermal conversion performance of the sample is excellent enough to destroy the pathological tissues, of which the temperature can be raised to 319.3 K after 180 s of near-infrared (NIR) irradiation with an invariable power density of 13.74 mW/mm 2 .…

Defect engineering, such as modification of oxygen vacancy density, has been considered as an effective approach to tailor the catalytic performance on transition-metal oxide nanostructured surfaces. The role of oxygen vacancies (O V ) on the surface of the as-prepared, zinnia-shaped morphology of CuO nanostructures and their marigold forms on calcination at 800 °C has been investigated through the study of model catalytic reactions of reduction of 4-nitrophenol and aerobic oxidation of benzyl alcohol. The O V on the surfaces of different morphologies of CuO have been identified and quantified through Rietveld analysis and HRTEM, EPR, and XPS studies. The structure–activity relationships between surface oxygen vacancies (O V ) and catalytic performance have been systematically investigated. The enhanced catalytic performance of the cubic CuO nanostructures compared to their as-prepared forms has been attributed to the formation of surface oxygen species on the reactive and dominant (110) surface that has low oxygen vacancy formation energy. The mechanistic role of surface oxygen…

High-performance warm-white light-emitting diode (LED) devices are in great demand toward green and comfortable solid-state lighting. Herein, we report a creative green-emission CaY 2 HfGa(AlO 4 ) 3:Ce 3+ phosphor. CaY 2 HfGa(AlO 4 ) 3:Ce 3+ compounds with different cerium ion doping contents have been successfully prepared through a conventional high-temperature solid-state method, and their phase and crystal structure have been revealed via the powder X-ray diffraction and Rietveld refinement. Impressively, the CaY 2 HfGa(AlO 4 ) 3:Ce 3+ phosphors exhibit a broad-band excitation, which well covers the wavelength region from the 300 to 500 nm, corresponding to the commercial blue-emitting LED chip. Upon 450 nm excitation, the optimal CaY 2 HfGa(AlO 4 ) 3:2%Ce 3+ sample shows an intense broad-band green emission (the corresponding testing spectral range: 460–750 nm) with a strongest peak about 534 nm. In addition, the CaY 2 HfGa(AlO 4 ) 3:2%Ce 3+ sample possesses a broad full width at half-maximum equal to 120 nm; moreover, its CIE chromaticity coordinate and the internal quantum…

Synthesis and structural depiction of two new metal–organic frameworks (MOFs), namely, [{Zn( L )(oba)}·4H 2 O] α (Zn-MOF -1 ) and [{Cd 1/2 ( L ) 1/2 (nipa) 1/2 (H 2 O) 1/2 }·(DMF) 1/2 (H 2 O)] α (Cd-MOF -2 ) (where L = N 2, N 6 -di(pyridin-4-yl)naphthalene-2,6-dicarboxamide, 4,4′-H 2 oba = 4,4′-oxybisbenzoic acid, and 5-H 2 nipa = 5-nitroisophthalic acid) are reported. Both Zn-MOF- 1 and Cd-MOF- 2 have been prepared by reacting ligand L and coligand 4,4′-H 2 oba or 5-H 2 nipa with the respective dihydrates of Zn(OAc) 2 and Cd(OAc) 2 (OAc = acetate). Crystal structure X-ray analysis discloses that Zn-MOF -1 displays an overall 2D → 3D interpenetrated framework structure. The topological analysis by ToposPro suggests a (4)-connected uninodal sql topology with a point symbol of {4 4 ·6 2 } having 2D + 2D parallel polycatenation. However, crystal packing of Cd-MOF -2 adapted a porous framework architecture and was topologically simplified as (3,4)-connected binodal 2D net. In addition, both Zn-MOF -1 and Cd-MOF -2 were proved to be multifunctional materials for the recognition of…

A multifunctional metal–organic framework, (Hdmbpy)[Dy(H 2 dobdc) 2 (H 2 O)]·3H 2 O ( Dy-MOF, H 4 dobdc = 2,5-dihydroxyterephthalic acid, dmbpy = 4,4′-dimethyl-2,2′-bipyridine), was synthesized and structurally characterized. The metal center Dy III is connected by four carboxyl groups to form the [Dy 2 (CO 2 ) 4 ] binuclear nodes, which are further interconnected by eight separate H 2 dobdc 2– ligands to form a three-dimensional (3D) framework including hydrophilic triangular channels and abundant hydrogen-bonding networks. Dy-MOF has good stability in aqueous solution as well as in harsh acidic or alkaline solutions (pH range: 2.0–12.0). Furthermore, the luminescence signal of Dy-MOF undergoes a visualized color change as the acidity of the solution alters, which is the typical behavior of pH ratiometric probe. At a 100% relative humidity, Dy-MOF exhibits a high proton conductivity σ (1.70 × 10 –4 S cm –1 at 303 K; 1.20 × 10 –3 S cm –1 at 343 K) based on the proton hopping mechanism, which can be classified as a superionic conductor with σ exceeding 10 –4 S cm –1 . Additionally,…

Ultrathin two-dimensional metal–organic frameworks (MOFs) have convincing performances in energy storage, which can be put down to their accessible active sites with rapid charge transfer. Herein, NiCo-layered double hydroxide (LDH) nanosheet arrays are used as self-sacrificial templates to in situ fabricate ultrathin NiCo-MOF nanosheet arrays on Ni foam (NS/NF) by using organic ligands without adding metal sources. Two ultrathin MOF nanosheets with different ligands, terephthalate (BDC) and 2-aminoterephthalate (NH 2 -BDC), are synthesized, characterized, and discussed in detail. Specifically, NiCo-NH 2 -BDC-MOF NS/NF exhibits the best electrochemical performance as a battery-type electrode for supercapacitors, achieves an areal capacitance of 12.13 F cm –2 at a current density of 2 mA cm –2, and retains the original capacitance of 73.08 % after 5000 cycles at a current density of 50 mA cm –2 . Furthermore, when NiCo-NH 2 -BDC-MOF NS/NF is assembled with activated carbon (AC) to form an asymmetric supercapacitor (ASC), an energy density of 0.81 mWh cm –2 can be provided at a power…

Encapsulation of nano-semiconductor materials in three-dimensional (3D) adsorbents to build a typical semiconductor-adsorbent heterostructure is a forward-looking strategy for photo-assisted uranium extraction. Here, we develop 3D MXene-derived TiO 2 (M)@reduced graphene oxide (RGO) aerogel for photo-assisted uranium extraction. Theoretical simulations demonstrate that oxygen vacancies on TiO 2 (M) tailor the energy level structure and enhance the electron accumulation at gap states of TiO 2 (M), thereby further realizing the spatial separation efficiency of electron–hole pairs by the Schottky junction. By virtue of the in situ X-ray photoelectron spectroscopy spectrum, we identify that photogenerated electrons generated over TiO 2 (M) were transferred to graphene oxide aerogel by the Schottky junction. Accordingly, TiO 2 (M)@RGO aerogel presents a considerable removal efficiency for U(VI) with a removal ratio of 95.7%. Relying on the X-ray absorption spectroscopy technique, we distinguish the evolution of 2H 2 O-2O ax -U-5O eq into H 2 O-2O ax -U-3O eq from dark to light…

Radioactive iodine ( 129 I and 131 I), produced or released from nuclear-related activities, posed severe effects on both human health and environment. The efficient removal of radioiodine from aqueous medium and vapor phase is of paramount importance for the sustainable development of nuclear energy. Herein, a metal–organic framework (MOF) nanosheet with a positive charge was constructed for the capture of iodine for the first time. The as-synthesized ultrathin nanosheets, with a thickness of 4.4 ± 0.1 nm, showed a record-high iodine adsorption capacity (3704.08 mg g –1 ) from aqueous solution, which is even higher than that from the vapor phase (3510.05 mg g –1 ). It can be ascribed to the fully interactions between the extensive accessible active sites on the largely exposed surface of 2D MOF nanosheets and the target pollutants, which also gave rise to fast adsorption kinetics with relative high removal efficiencies in the low concentrations, even in seawater. Moreover, a facile recyclability with fast desorption kinetics can also be achieved for the MOF nanosheets. The…

Attracted by the exceptional structural rigidity and inherent porous structures of the Hf-based metal–organic frameworks (MOFs), we adopted a rapid synthesis approach to preparing three nanoscale MOFs, Hf-UiO-66 ( 1 ), Hf-UiO-66-(OH) 2 ( 2 ), and Hf-UiO-66-NH 2 ( 3 ), and systematically explored the water-assisted proton conductivities of the original ones and the post-modified products. Interestingly, the proton conductivities (σ) of all three MOFs exhibit significant temperature and humidity dependence. At 98% RH and 100 °C, their optimal σ values can reach up to 10 –3 S·cm –1 . Consequently, imidazole units are loaded into 1–3 to obtain related MOFs, Im@1, Im@2, and Im@3, and the σ values of the imidazole-loaded products are boosted to 10 –2 S·cm –1 . Note that these modifications not only do not change the frameworks of the pristine MOFs but also do not affect their high chemical and water stability. The proton-conductive mechanisms of these MOFs before and after modification have been thoroughly discussed based on structural analyses, N 2 and H 2 O vapor adsorptions, and…

Interior and surface synergistic modifications can endow the photocatalytic reaction with tuned photogenerated carrier flow at the atomic level. Herein, a new class of 2D/2D SnNb 2 O 6 /Ni-doped ZnIn 2 S 4 (SNO/Ni-ZIS) S-scheme heterojunctions is synthesized by a simple hydrothermal strategy, which was used to evaluate the synergy between interior and surface modifications. Theoretical calculations show that the S-scheme heterojunction boosts the desorption of H atoms for rapid H 2 evolution. As a result, 25% SNO/Ni 0.4 -ZIS exhibits significantly improved PHE activity under visible light, roughly 4.49 and 2.00 times stronger than that of single ZIS and Ni 0.4 -ZIS, respectively. In addition, 25% SNO/Ni 0.4 -ZIS also shows superior structural stability. This work provides advanced insight for developing high-performance S-scheme systems from photocatalyst design to mechanistic insight.

Energy saving and emission reduction have always been the goal of separation and catalysis pursued in industrial production. Metal–organic frameworks (MOFs) are leading porous crystal materials with unique advantages in these fields. Based on an amide-modified ligand 5-(ethyl oxamate)-isophthalic acid (H 2 EtL), a new porous indium-organic framework (Me 2 NH 2 ) 1.5 [In 1.5 L 2 ]·2DMF·2H 2 O ( 1 ) was synthesized and structurally characterized. The unique porous environment gives it dual functional advantages in separation and catalysis. At room temperature, 1 possesses excellent adsorption capacities for C 2 hydrocarbons and CO 2, showing good separation behaviors for C 2 hydrocarbons/CO 2 on CH 4 and C 2 H 2 on CO 2, which is conducive to efficient purification of CH 4 and C 2 H 2 confirmed by the breakthrough experiment. Meanwhile, catalytic results indicate that 1 can be used as a good catalyst for effective fixation of CO 2 under mild conditions to form cyclic carbonates.

Fabrication of sintering- and carbon-free Ni catalysts for methane dry reforming (MDR), which is attractive to upgrade greenhouse gases CH 4 and CO 2, is challenging. In this work, we innovatively synthesized Ni–Cu alloy nanoparticles confined by physical encapsulation and chemical metal–support interaction (MSI); the synergism of alloy effect, size effect, MSI, and confinement effect in the catalysts gave high rates of CH 4 and CO 2 of 6.98 and 7.16 mmol/(g Ni s), respectively, at 1023 K for 50 h. The rates were 2–3 times enhanced compared to those in the literature. XRD, TEM, H 2 -TPR, and so forth revealed that the alloy effect, size effect, and MSI of Ni–Cu and CeO 2 enhanced the MDR activity; MSI promoted the ceria surface lattice oxygen mobility and generated more oxygen vacancies, almost completely gasifying carbon deposits; chemical confinement from MSI and physical confinement from SiO 2 nanospheres realized sintering-free alloys and CeO 2 nanoparticles. The synergistic approach provides a universal strategy for sintering- and carbon-free Ni catalyst design for MDR reaction.

MXenes, a large family of two-dimensional (2D) transition-metal carbides/nitrides, have attracted increased attention in recent years because of their excellent electronic, mechanical, thermal, and optical properties. Studying chemical properties of MXenes is important to prolong the shelf life of their colloids and provide robust performance of MXenes in devices and applications. While the role of MXene reactivity with the environment, including water and components of air, is becoming more recognized, less is known about the role of parameters influencing the reactivity. In this work, we investigate the individual and combined effects of the pH and antioxidant on chemical stability of Ti 2 CT x, Ti 3 CNT x, and Ti 3 C 2 T x MXenes using GC, XPS, UV–vis, and Raman spectroscopy. In contrast to indirect indicators of MXene degradation, such as film conductivity or performance in electrochemical energy storage systems, we focus on detection of reaction products as the most sensitive and direct way of monitoring the chemical transformations of MXenes. Based on our knowledge of MXene…

Electrochemical reduction of NO to NH 3 is of great significance for mitigating the accumulation of nitrogen oxides and producing valuable NH 3 . Here, we demonstrate that the CoS nanosheet with sulfur vacancies (CoS 1– x ) behaves as an efficient catalyst toward electrochemical NO-to-NH 3 conversion. In 0.2 M Na 2 SO 4 electrolyte, such CoS 1– x displays a large NH 3 yield rate (44.67 μmol cm –2 h –1 ) and a high Faradaic efficiency (53.62%) at −0.4 V versus the reversible hydrogen electrode, outperforming the CoS counterpart (27.02 μmol cm –2 h –1; 36.68%). Moreover, the Zn–NO battery with CoS 1– x shows excellent performance with a power density of 2.06 mW cm –2 and a large NH 3 yield rate of 1492.41 μg h –1 mg cat. –1 . Density functional theory was performed to obtain mechanistic insights into the NO reduction over CoS 1– x .

In this work, the advantages of in situ loading, heterojunction construction, and facet regulation were integrated based on the poly-facet-exposed BiOCl single crystal, and a facet-oriented supported heterojunction of Cu 2 O and BiOCl was fabricated (Cu 2 O@BiOCl[100]). The photocatalytic nitrogen reduction reaction (pNRR) activity of Cu 2 O@BiOCl[100] was as high as 181.9 μmol·g –1 ·h –1, which is 4.09, 7.13, and 1.83 times that of Cu 2 O, BiOCl, and Cu 2 O@BiOCl-ran (Cu 2 O randomly supported on BiOCl). Combined with the results of the photodeposition experiment, X-ray photoelectron spectroscopy characterization, and DFT calculation, the mechanism of Cu 2 O@BiOCl[100] for pNRR was discussed. When Cu 2 O directionally loaded on the [100] facet of BiOCl, electrons generated by Cu 2 O will be transmitted to the [100] facet of BiOCl through Z-scheme electron transmission. Due to the directional separation characteristics of charge in BiOCl, the electrons transmitted from Cu 2 O are enriched on the [001] facet of BiOCl, which will together with the original electrons generated by…

Mechanoluminescence materials that emit light under mechanical stimulation have attracted widespread attention in sensing, anticounterfeiting, and imaging applications. In this study, a series of Sr 1– x Bi x ZnSO (0.001 ≤ x ≤ 0.1) samples was synthesized by the method of high temperature solid-state reaction. It is worth noting that the distortion degree of the SrO 3 S 3 octahedron was increased with increasing Bi 3+ concentration, and the color manipulated Sr 1– x Bi x ZnSO which can emit different photoluminescence (blue to dark blue and finally red) and mechanoluminescence (orange to red) colors is obtained. Moreover, the deep traps can stably store and provide electronic supplements in shallow traps released under mechanical stimulation. Therefore, devices made of SrZnSO:Bi 3+ phosphor and polydimethylsiloxane (PDMS) can be used as thermo-mechano-opto three-mode anticounterfeiting. The ML intensity is linear to the external load and can be utilized for stress sensing or imaging.

A Ce/Ti-based bimetallic 2-aminoterephthalate metal–organic framework (MOF) was synthesized and evaluated for photocatalytic reduction of CO 2 in comparison with an isoreticular pristine monometallic Ce-terephthalate MOF. Owing to highly selective CO 2 adsorption capability, optimized band gaps, higher flux of photogenerated electron–hole pairs, and a lower rate of recombination, this material exhibited better photocatalytic reduction of CO 2 and lower hydrogen evolution compared to Ce-terephthalate. Thorough probing of the surface and electronic structure inferred that the reducibility of Ce 4+ to Ce 3+ was due to the introduction of an amine functional group into the linker, and low-lying Ti(3 d ) orbitals in Ce/Ti-2-aminoterephthalate facilitated the photoreduction reaction. Both the MOFs were calcined to their respective oxides of Ce 1– x Ti x O 2 and CeO 2, and the electrocatalytic reduction of CO 2 was performed over the oxidic materials. In contrast to the photocatalytic reaction mechanism, the lattice substitution of Ti in the CeO 2 fluorite cubic structure showed a better…

A series of heteroleptic square-planar Pt and Pd complexes with bis(diisopropylphenyl) iminoacenaphtene (dpp-Bian) and Cl, 1,3-dithia-2-thione-4,5-dithiolate (dmit), or 1,3-dithia-2-thione-4,5-diselenolate (dsit) ligands have been prepared and characterized by spectroscopic techniques, elemental analysis, X-ray diffraction analysis, and cyclic voltammetry (CV). The intermolecular noncovalent interactions in the crystal structures were assessed by density functional theory (DFT) calculations. The anticancer activity of Pd complexes in breast cancer cell lines was limited by their solubility. Pd(dpp-Bian) complexes with dmit and dsit ligands as well as an uncoordinated dpp-Bian ligand were devoid of cytotoxicity, while the [Pd(dpp-Bian)Cl 2 ] complex was cytotoxic. On the contrary, all Pt(dpp-Bian) complexes demonstrated anticancer activity in a low micromolar concentration range, which was 8–20 times higher than the activity of cisplatin, and up to 2.5-fold selectivity toward cancer cells over healthy fibroblasts. The presence of a redox-active dpp-Bian ligand in Pt and Pd complexes…

Broadband near-infrared (NIR) phosphors are necessary materials for developing portable NIR light sources. Moreover, exploiting an NIR phosphor with a main peak located beyond a wavelength of 900 nm remains a challenge because this spectral range has great potential in biological nondestructive testing and solution testing. In this study, a range of Cr 3+ -doped ZnTa 2 O 6 (ZTO) phosphors were completely synthesized by a solid-state method, which show broadband Cr 3+ emission centered at 935 nm with a large full width at half maximum (FWHM) of 185 nm due to two distorted octahedral sites. A packaged phosphor-converted light-emitting diode (pc-LED) device is used to penetrate a 5-cm-thick chicken breast and identify diverse solutions based on differences in the measured transmission spectra. The results indicate broad application prospects in the field of biological tissue penetration and solution analysis.

High-performance microwave-absorbing materials (MAMs) derived from metal–organic frameworks (MOFs) have attracted considerable attention due to their tunable chemical composition and microstructure. In this contribution, a core–shell-structured Co/MnO/C nanocomplex was prepared using a CoMn-MIL MOF by a facile hydrothermal synthesis and subsequent pyrolysis process. The optimal microwave absorption (MA) property of the as-prepared Co/MnO/C nanocomplex was achieved by the regulation of the Co 2+ /Mn 2+ molar ratio. The minimum reflection loss (RL min ) of the Co/MnO/C-31 nanocomplex was low to −55.0 dB at 16.2 GHz with a thickness of 1.49 mm, and the effective absorption bandwidth (EAB) was high to 5.95 GHz (12.05–18 GHz) at a thickness of 1.8 mm. The mixed-metal nanocomplex with the core–shell structure exhibited outstanding MA performance, corresponding to the synergetic effect of the magnetic and dielectric loss. It provides a high efficiency strategy for rendering low reflection loss and broad EAB to high-performance MAMs.

To generate green hydrogen by water electrolysis, it is vital to develop highly efficient electrocatalysts for the oxygen evolution reaction (OER). The utilization of various 3d transition metal-based layered double hydroxides (LDHs), especially NiFe–LDH, has gained vast attention for OER under alkaline conditions. However, the lack of a proper electronic structure of the NiFe–LDH and low stability under high-pH conditions limit its large-scale application. To overcome these difficulties, in this study, we constructed an Sn-doped NiFe–LDH material using a simple wet-chemical method. The doping of Sn will synergistically increase the active surface sites of NiFe–LDH. The highly active NiFe–LDH Sn 0 . 015(M) shows excellent OER activity by requiring an overpotential of 250 mV to drive 10 mA/cm 2 current density, whereas the bare NiFe–LDH required an overpotential of 295 mV at the same current density. Also, NiFe–LDH Sn 0 . 015(M) shows excellent long-term stability for 50 h in 1 M KOH and also exhibits a higher TOF value of 0.495 s –1, which is almost five times higher than that of…

Herein, we have successfully synthesized binary Ag 2 Se, composite Ag 0:Ag 2 Se, and ternary Cu +:Ag 2 Se through an ambient aqueous-solution-based approach in a one-pot reaction at room temperature and atmospheric pressure without involving high-temperature heating, multiple-processes treatment, and organic solvents/surfactants. Effective controllability over phases and compositions/components are demonstrated with feasibility for large-scale production through an exquisite alteration in reaction parameters especially pH for enhancing and understanding thermoelectric properties. Thermoelectric ZT reaches 0.8–1.1 at near-room-temperature for n-type Ag 2 Se and Cu + doping further improves to 0.9–1.2 over a temperature range of 300–393 K, which is the largest compared to that reported by wet chemistry methods. This improvement is related to the enhanced electrical conductivity and the suppressed thermal conductivity due to the incorporation of Cu + into the lattice of Ag 2 Se at very low concentrations ( x %Cu +:Ag 2 Se, x = 1.0, 1.5, and 2.0).

Chemotherapy is still an important and effective clinical treatment for cancer. However, individual drugs hardly achieve precise controlled release and targeted therapy, thus resulting in unavoidable side effects. Fortunately, the emergence of drug carriers is expected to solve the above problems. In this work, the MOF-on-MOF strategy was adopted to encapsulate DOX into double-layer NH 2 -MIL-88B to fabricate a core–shell-structured DOX@NH 2 -MIL-88B-On-NH 2 -MIL-88B (DMM) and then realize the pH and GSH dual-responsive controlled DOX release. Because of the core–shell structure, the drug-loading capacity of DMM reached 14.4 wt %, which was nearly twice that of DOX@NH 2 -MIL-88B (DM), and the controlled release performance of DMM was also improved at the same time, greatly improving the kinetics equilibrium time of DOX from 2 h (DM) to 16 h (DMM) at pH 5.0. Moreover, we found that DMM also possessed peroxidase-like catalytic activity under acidic conditions, which could catalyze H 2 O 2 to produce • OH, exhibiting the potential chemodynamical treatment of cancer. Cell experiments…

Excessive content of fluoride ions (F – ) in water will lead to water pollution and endanger human health, so the research on the method of low-cost, rapid, and efficient detection of F – is of particular significance. In this work, an amino-functionalized ligand with an appropriate triplet energy excited state, 2′-amino-[1,1′:4′,1″-terphenyl]-3,3″,5,5″-tetracarboxylic acid (H 4 TPTC-NH 2 ), was selected to construct a luminescent single-lanthanide metal–organic framework, EuTPTC-NH 2, with uncoordinated amino groups for the detection of F – . Based on host–guest interactions, that is, hydrogen bonds formed between the free amino groups and F – ions, EuTPTC-NH 2 was developed as a ratiometric fluorescence probe for F – detection with good anti-interference ability, low detection limit, high water stability, and selectivity. It was found that EuTPTC-NH 2 has an excellent linear response to F – in the concentration range of 0–80 μM with high sensitivity and a low detection limit of 11.26 μM. A hydrogel membrane based on the combination of EuTPTC-NH 2 and agarose was also prepared for…

Bimetallic metal–organic frameworks (MOFs) with an ultrathin configuration are compelling materials for developing high-performance energy storage devices on account of their unique structural merits. Herein, a hydrangea-like NiCo-MOF is well prepared using controllable solvothermal and cation-exchange processes, synchronously achieving bimetallic nodes and hierarchical ultrathin architecture. The structural superiority enables NiCo-MOF of expanded electrons’ transfer pathways and multitudinous electrolytes’ diffusion channels, resulting in a significant enhancement in pseudocapacitive performance. Coupling with the bimetallic nature and constructional advantages, NiCo-MOF shows superior gravimetric capacity (832.6 C g –1 at 1 A g –1 ) and electrochemical kinetics to those of monometallic Ni-MOF and Co-MOF. Importantly, the quasi-solid-state hybrid supercapacitor (HSC) based on the NiCo-MOF cathode and active carbon (AC) anode delivers a desirable energy density (45.3 Wh kg –1 at 847.8 W kg –1 ), a favorable power density (7160.0 W kg –1 at 23.3 Wh kg –1 ), a remarkable cyclability…

Electrochemical nitrate (NO 3 – ) reduction is a potential approach to produce high-value ammonia (NH 3 ) while removing NO 3 – pollution, but it requires electrocatalysts with high efficiency and selectivity. Herein, we report the development of Fe 3 O 4 nanoparticles decorated TiO 2 nanoribbon array on titanium plate (Fe 3 O 4 @TiO 2 /TP) as an efficient electrocatalyst for NO 3 – -to-NH 3 conversion. When operated in 0.1 M phosphate-buffered saline and 0.1 M NO 3 –, such Fe 3 O 4 @TiO 2 /TP achieves a prominent NH 3 yield of 12394.3 μg h –1 cm –2 and a high Faradaic efficiency of 88.4%. In addition, it exhibits excellent stability during long-time electrolysis.

This work presents three series of Eu/Tb metal–organic frameworks (MOFs) containing benzophenone-4,4′-dicarboxylic acid (H 2 BPNDC), 4,4′-dicarboxydiphenyl ether (H 2 OBA), and terephthalic acid (H 2 BDC) as the ligands. Eu/Tb MOFs have the same structural features in that their 3D frameworks are simplified as 2,3,10-connected {4 2 .6} 2 {4 6 .6 18 .8 19 .10 2 }{4} 2 topological networks. The solid-state fluorescence spectra of three Eu/Tb MOF series are attributed to the combined emissions of 5 D 0 → 7 F J ( J = 1–4) transitions in Eu 3+ and 5 D 4 → 7 F J ( J = 6–5) transitions in Tb 3+ . The n Eu: n Tb of Eu/Tb MOFs is optimized as 1:69 based on the relationships between I Tb(545) / I Eu(614) and n Eu: n Tb; that is, Eu 0.0143 Tb 0.9857 -L (L = BPNDC 2–, OBA 2–, and BDC 2– ) were selected to carry out the following temperature ( T )-sensing tests. The fluorescence mechanism of Eu 0.0143 Tb 0.9857 -L can be explained by a ligand-to-metal charge transfer combined with an intermetallic Tb 3+ → Eu 3+ energy transfer. The T -dependent fluorescence indicates linear relationships with…

Not only a critical matter in the nuclear fuel cycle but uranium is also a global contaminant with both radioactive and chemical toxicity. Reducing soluble hexavalent uranium [U(VI)] to relatively nonimmigrated tetravalent uranium [U(IV)] by photocatalytic technologies is recognized as a highly promising strategy for avoiding environmental pollution and re-extracting uranium resources from nuclear wastewater. Herein, we have designed a heterojunction photocatalyst constructed from the carbon aerogels (CA) and the CdS nanoflowers with an S-vacancy (CA@CdS-SV). With the S-vacancy and heterojunction being synergized, the U(VI) removal rate exceeded 97% in 40 min without the addition of any sacrificial agents. As impacted by the synergistic effects of the S-vacancy and heterojunction, thermodynamics and kinetics revealed that photogenerated electrons were first captured via shallow traps generated by vacancies on CdS-SV and then transferred to the CA surfaces through the heterojunction to realize the spatial separation of carriers, thereby achieving a satisfactory performance. This work…

Density functional theory (DFT) calculations have been conducted to investigate the mechanism of cobalt(II) tetraamino phthalocyanine ( CoPc-NH 2 ) catalyzed electro-reduction of CO 2 . Computational results show that the catalytically active species 1 ( 4 [Co II (H 4 L)] 0 ) is formed by a four-electron-four-proton reduction of the initial catalyst CoPc-NH 2 . Complex 1 can attack CO 2 after a one-electron reduction to give a [Co III –CO 2 2– ] − intermediate, followed by a protonation and a one-electron reduction to give intermediate [Co II –COOH] − ( 4 ). Complex 4 is then protonated on its hydroxyl group by a carbonic acid to generate the critical species 6 (Co III –L •– –CO), which can release the carbon monoxide as an intermediate (and also as a product). In parallel, complex 6 can go through a successive four-electron-four-proton reduction to produce the targeted product methanol without forming formaldehyde as an intermediate product. The high-lying π orbital and the low-lying π* orbital of the phthalocyanine endow the redox noninnocent nature of the ligand, which could be a…

values are in good agreement with the ones obtained theoretically in this work.

A unique hydrogen-bonded organic–inorganic framework (HOIF) constructed from a mononuclear cobalt(II) complex, [Co(MCA) 2 ·(H 2 O) 2 ] (HMCA = 4-imidazolecarboxylic acid), via multiple hydrogen-bonding interactions was synthesized and structurally characterized. The Co(II) center in the HOIF features a highly distorted octahedral coordination environment. Remarkably, the Co II HOIF showed permanent porosity with superior stability as established by combined thermogravimetric analysis (TGA), variable-temperature infrared spectra (IR), variable-temperature powder X-ray diffraction data (PXRD), and a CO 2 isotherm. Structural studies reveal that short multiple hydrogen bonds should be responsible for the superior thermal and chemical stability of a HIOF. Magnetic investigations reveal the large easy-plane magnetic anisotropy of the Co 2+ ions with the fitted D values being 22.1 (magnetic susceptibility and magnetization data) and 29.1 cm –1 (reduced magnetization data). In addition, the HOIF exhibits field-induced slow magnetic relaxation at low temperature with an effective energy…

We report a comprehensive assessment of Lewis acidity for a series of carbone-stibenium and -bismuthenium ions using the Gutmann–Beckett (GB) method. These new antimony and bismuth cations have been synthesized by halide abstractions from (CDC)PnBr 3 and [( py CDC)PnBr 2 ][Br] (CDC = carbodicarbene; Pn = Sb or Bi; py = pyridyl). The reaction of (CDC)SbBr 3 ( 1 ) with one or two equivalents of AgNTf 2 (NTf 2 = bis(trifluoromethanesulfonyl)imide) or AgSbF 6 gives stibaalkene mono- and dications of the form [(CDC)SbBr 3– n ][A] n ( 2–4; n = 1,2; A = NTf 2 or SbF 6 ). The stibaalkene trication [(CDC) 2 Sb][NTf 2 ] 3 ( 5 ) was also isolated and collectively these molecules fill the gap among the series of cationic pnictaalkenes. The Sb cations are compared to the related CDC-bismaalkene complexes 6 – 9 . With the goal of preparing highly Lewis acidic compounds, a tridentate bis(pyridine)carbodicarbene ( py CDC) was used as a ligand to access [( py CDC)PnBr 2 ][Br] ( 10, 12 ) and trications [( py CDC)Pn][NTf 2 ] 3 (Pn = Sb ( 11 ), Bi ( 13 )), forgoing the need for a second CDC as used in…

Developing highly efficient photocatalysts toward synchronously removing heavy metals and organic pollutants is still a serious challenge. Herein, we depict hierarchical S-scheme heterostructured photocatalysts prepared via in situ anchoring UiO-66-NH 2 nanoparticles onto the CdIn 2 S 4 porous microsphere structures assembled with numerous nanosheets. In the mixed system of Cr(VI) and tetracycline (TC), the optimal photocatalyst (CIS@U66N-30) shows remarkable photocatalytic activities toward the synchronous removal of Cr(VI) (97.26%) and TC (close to 100% of) under visible-light irradiation for 60 min, being the best removal rates among those of the reported photocatalysts, and sustains the outstanding stability and reusability. Its reaction rate constants of Cr(VI) reduction and TC degradation are about 2.06 and 1.58 folds that in the single Cr(VI) and TC systems, respectively. The enhanced photocatalytic activities of CIS@U66N-30 mainly result from the following synergism: (1) its hierarchical structure offers abundant active sites, and the S-scheme migration mechanism of charge…

Stereochemically active lone-pair (SCALP) cations are one attractive type of nonlinear optical (NLO)-active units because of their large microcosmic polarizability and anisotropy. Currently, the single and/or dual lone-pair cation-based noncentrosymmetric (NCS) oxides have been extensively investigated and verified to be one class of outstanding NLO materials. From the perspective of function optimization, the integration of three kinds of SCALP cations into one crystal may synergistically improve the NLO properties, which is greatly expected but unexplored to date. Herein, by introducing flexible metal halide bonds to guarantee the stereochemical activity and overcome the energetically favorable antiparallel arrangements of lone-pair cations, the first type of three lone-pair-cation (Pb 2+, Bi 3+, and Se 4+ )-coexisting NCS oxides PbBi(SeO 3 ) 2 F ( I ) and Pb 2 Bi(SeO 3 ) 2 Cl 3 ( II ) was obtained. As expected, both compounds show outstanding NLO properties, such as the strong second-harmonic-generation signal (10.5× and 13.5 × KDP), large birefringence (0.103 and 0.186),…

A multifunctional Cd-based coordination polymer based on a viologen derivative and a secondary carboxylic ligand, namely, {[Cd 2 (bcbp)(pta) 2 (H 2 O)]·2H 2 O} n ( 1, H 2 bcbpCl 2 = 1,1′-bis(4-carboxyphenyl)-(4,4′-bipyridinium) dichloride, H 2 pta = p -phthalic acid), has been solvothermally synthesized and structurally characterized. Compound 1 is a 3D framework built on {Cd 2 (pta) 2 (H 2 O)} n net with square channels which intalls bcbp ligands at the diagonal position of the two adjacent square channels. Notably, compound 1 exhibits a reversible photochromic transformation between yellowish gray and dark green under xenon light irradiation, which should be attributed to the formation of free viologen radicals. Furthermore, compound 1 also displays a chemochromic phenomenon from yellowish gray to dark green after exposure to ammonia and hydrazine, which could be ascribed to the generation of viologen radicals and charge-transfer complexes triggered by nucleophilic attack of electron-rich ammonia and hydrazine molecules to the electron-deficient viologen moiety in the bcbp ligand.…

Multicolor-emission-based single-phase white light derived from different luminescence centers is an effective way to manipulate the optical properties of halide perovskites. In this work, we developed a codoping strategy to incorporate Bi 3+ and Te 4+ emission centers into all-inorganic lead-free Cs 2 HfCl 6 perovskite by a hydrothermal method. The as-prepared Bi 3+ /Te 4+ -doped Cs 2 HfCl 6 microcrystals show bright blue (Bi 3+ ), yellow (Te 4+ ), and warm-white emissions (Bi 3+ /Te 4+ ), respectively. The broad efficient dual emission in Bi 3+ /Te 4+ co-doped Cs 2 HfCl 6 is assigned to the typical 3 P 1 → 1 S 0 transition emission from Bi 3+ originating from [Bi Hf + V Cl ] and self-trapped excitons (STEs) from Te 4+ . Moreover, the concentration-optimized Cs 2 HfCl 6:Te 4+ shows excellent antiwater stability and high photoluminescence quantum yield (PLQY) of ∼70%. Meanwhile, a white light-emitting diode (WLED) fabricated using Bi 3+ /Te 4+ co-doped Cs 2 HfCl 6 is close to warm white with a color rendering index (CRI) of 75.4, CIE color coordinate of (0.370, 0.393), and a…

In recent years, molecular perovskite energetic materials have attracted more attention because of their simple synthesis processes, high thermal stabilities, excellent performances, and great significance as a design platform for energetic materials. To explore the possibility of the application of molecular perovskite energetic materials in heat-resistant explosives, four silver(I)-based molecular perovskite energetic compounds, (H 2 A)[Ag(ClO 4 ) 3 ], where H 2 A = piperazine-1,4-diium (H 2 pz 2+ ) for PAP-5, 1-methyl-piperazine-1,4-diium (H 2 mpz 2+ ) for PAP-M5, homopiperazine-1,4-diium (H 2 hpz 2+ ) for PAP-H5, and 1,4-diazabicyclo[2.2.2]octane-1,4-diium (H 2 dabco 2+ ) for DAP-5, were synthesized by a one-pot self-assembly strategy and structurally characterized. The single-crystal structures indicated that PAP-5, PAP-M5, and DAP-5 possess cubic perovskite structures while PAP-H5 possesses a hexagonal perovskite structure. Differential thermal analyses showed that their onset decomposition temperatures are >308.3 °C. For PAP-5 and DAP-5, they have not only exceptional…

Os(II) complexes showing singlet-to-triplet absorption are of growing interest as a new class of triplet sensitizers that circumvent energy loss during intersystem crossing, and they enable effective utilization of input photon energy in various applications, such as photoredox catalysis, photodynamic therapy, and photon upconversion. However, triplet excited-state lifetimes of Os(II) complexes are often too short (τ < 1 μs) to transfer their energy to neighboring molecules. While the covalent conjugation of chromophores has been known to extend the net excited-state lifetimes through an intramolecular triplet energy transfer (IMET), heavy-atom effects of the central metals on the attached chromophore units have rarely been discussed. Here, we investigate the relationship between the spin-density contribution of the heavy metals and the net triplet excited-state lifetimes for a series of Os(II) and Ru(II) bis(terpyridine) complexes modified with perylene units. Phosphorescence lifetimes of these compounds strongly depend on the lifetimes of the perylenyl group-localized excited…

Multicomponent metal-organic frameworks (MOFs) have received an increasing amount of attention due to their potential to produce new topologies, pore metrics, and functionalities compared to MOFs with a single metal cluster and one organic linker. Herein, five isoreticular Zn MOFs were obtained by mixing two types of linear ditopic linkers in a one-pot solvothermal synthesis. Interestingly, in the resulting Zn MOFs a six-connected cyclic trinuclear Zn(II) cluster and an eight-connected linear trinuclear Zn(II) cluster coexist, leading to an uncommon (6,8)-connected network. Catalytic activities toward the solvent-free Knoevenagel reactions were observed for all of these MOFs. Further experimental and computational studies suggest that they are Brønsted acid-base bifunctional catalysts. Through chemical modifications of dicarboxylate ligands, including their aromatic backbones and substituents, we have successfully implemented reticular chemistry for the modulations of pore sizes, surface areas, and catalytic performances in a series of four-component isoreticular MOFs.

Owing to the extensive requirement for renewable energy sources such as hydrogen, great efforts are being devoted to optimizing the active ingredients for advanced hydrogen storage. In this regard, an ideal spinel-perovskite nanocomposite based on Li–Mn–Fe–Si materials was successfully fabricated via a one-pot hydrothermal route to store hydrogen electrochemically. To optimize both the phase composition and morphological features of nanostructures, the reaction was engineered under different conditions. Li–Mn–Fe–Si spinel-perovskite diphase structures were created with diverse shapes of polyhedral-shaped bulk particles, nanoparticles, nanoplates, and hierarchical structures. The alteration of multiple factors such as hydrothermal reaction time, temperature, polymeric surfactant type, and calcination temperature was surveyed to achieve the optimized size and morphology of the nanoproducts to be obtained. The morphological changes, structural regulations, porosity, and magnetic properties of the nanosized products were studied via field-emission scanning electron microscopy (FE-SEM),…

Stable stimulus-responsive materials are highly desirable due to their widespread potential applications and growing demand in recent decades. Despite the fact that viologen derivatives have long been known as excellent photochromic and electrochromic materials, the development of stable viologen-based multifunctional smart materials with short coloration times remains an exciting topic. To obtain photochromic and electrochromic dual responsive materials, embedding the viologen ligand into a robust metal oxide cluster to increase its stability and sensitivity is an effective strategy. Herein, a viologen-based metal–organic polyhedron (MOP) {[Zr 6 L 3 (μ 3 -O) 2 (μ 2 -OH) 6 Cp 6 ]·8Cl·CH 3 OH·DMF} [ Zr-MOP-1; H 2 L·2Cl = 1,1′-bis(4-carboxyphenyl)-4,4′-bipyridinium dichloride, and Cp = η 5 -C 5 H 5 ] was successfully prepared and characterized. It consists of trinuclear Zr–oxygen secondary building units and exhibits reversible photochromic and electrochromic dual responsive behaviors. As expected, the designed robust viologen-based nanocage with a V 2 E 3 (V = vertex, and E = edge)…

The catalytic performance of metal–organic framework (MOF)-based catalysts can be enhanced by increasing their catalytic sites, which prompts us to explore the multicore cluster-based skeletons by using designed functional ligands. Herein, the exquisite combination of [Tb 4 (μ 2 –OH) 2 (CO 2 ) 8 ] cluster and 2,6-bis(2,4-dicarboxylphenyl)-4-(4-carboxylphenyl)pyridine (H 5 BDCP) ligand generated a highly robust nanoporous framework of {[Tb 4 (BDCP) 2 (μ 2 –OH) 2 ]·3DMF·5H 2 O} n ( NUC-58 ), in which each four {Tb 4 } clusters are woven together to generate an elliptical nanocage (aperature ca. 12.4 Å). As far as we know, NUC-58 is an excellent nanocage-cluster-based {Tb 4 }-organic framework with the outstanding confined pore environments of a large specific surface area, high porosity, and plentiful coexisting Lewis acid–base sites of Tb 3+, μ 2 –OH and N pyridine atoms. Performed experiments exhibited that NUC-58 owns a better catalytic performance for the cycloaddition reactions under mild conditions with a high turnover number and turnover frequency. Furthermore, NUC-58, as an…

How to accurately detect and efficiently sweep Cr(VI) from contaminated water has come into focus. Zirconium-based metal–organic frameworks (MOFs) play vital roles in water environmental chemistry due to excellent hydrolysis-resistant stability. However, as photochemical probes and photocatalysts, poor performances in detection sensitivity, selectivity, and photosensitiveness limit sole Zr-MOFs’ applications. So, it is urgent to quest valid strategies to break through the dilemmas. Embedding luminous dyes into MOFs has been considered one of the most feasible avenues. Herein, a dual-emissive RhB@Zr-MOF with orange-yellow fluorescence has been assembled by in situ-encapsulating rhodamine B (RhB) into a zirconium–biquinoline-based MOF. Actually, within RhB@Zr-MOF, the aggregation fluorescence quenching (ACQ) effect of RhB molecules was effectively avoided. Notably, RhB@Zr-MOF exhibits a rapid fluorescence quenching response toward Cr(VI) ions with high selectivity, sensitivity, and anti-interference abilities. More interestingly, unlike the most widely reported fluorescence resonance…

Visible-light-driven organic transformation photocatalyzed by metal–organic frameworks (MOFs) under mild conditions is considered a feasible route to conserve energy and simplify synthesis. Herein, a light-sensitized, three-dimensional uranyl–organic framework ( HNU-64 ) with twofold interpenetration and its derivatives HNU-64-CH 3 and HNU-64-Cl with functionalized ligands of −CH 3 and −Cl groups were obtained. These MOFs have broad optical absorption bands and suitable band energy levels in photooxidation, which makes them exhibit high activity and selectivity for the photooxidation of benzylamine to N-benzylbenzoimide under mild conditions. This work provides an efficient and simple synthetic option for oxidative coupling of amines to directly produce imines.

Photocatalytic CO 2 reduction technology is of great importance to alleviate energy crisis and environmental pollution; however, it remains a serious challenge due to the fast recombination of carriers. In this study, we report a three-dimensional structure of a ZnIn 2 S 4 /Au/CdS composite photocatalyst for the CO 2 reduction reaction, where Au nanoparticles (NPs) are evenly anchored on the surface of ZnIn 2 S 4 by photodeposition and Au NPs are wrapped around by CdS. In ZnIn 2 S 4 /Au/CdS composite photocatalysts, Au NPs act as a bridge to construct a “semiconductor–metal–semiconductor” tandem electron transfer mechanism (ZnIn 2 S 4 → Au → CdS) heterojunction, which greatly promotes the transfer of photogenerated electrons. It is worth noting that Au NPs, as a local surface plasmon resonance (LSPR) effect excited source to generate excited-state electrons, further improve the photoreduction CO 2 activity. Under UV–vis light irradiation, the CO yield of ZnIn 2 S 4 /Au/CdS can reach 63.07 μmol·g –1 ·h –1, which is higher than that of 6.37 μmol·g –1 ·h –1 for pure ZnIn 2 S 4, 0.93…

Physiological storage disorders are caused by ineffective post-harvest handling of horticultural crops, particularly fruits. To address these post-harvest concerns, diphenylamine (DPAH •+ ) is widely used as a preservative to prevent fruit degradation and surface scald during storage around the world. Humans are negatively affected by the use of high concentrations of DPAH •+ because of the various health complications related to its exposure. As a result, accurate detection and quantification of DPAH •+ residues in treated fruits are critical. Rare earth metal orthovanadates, which have excellent physical and chemical properties, are potential materials for electrochemical sensors in this area. Herein, we present a simple and direct ultrasonication technique for the surfactant-assisted synthesis of praseodymium orthovanadate (PrVO 4 or PrV) loaded on nickel iron layered double hydroxide (NiFe-LDH) synthesized with deep eutectic solvent assistance, as well as its application as an effective catalyst in the detection and degradation of DPAH •+ in fruits and water samples. The current…

Cost-effective adsorption-based C 2 H 2 /C 2 H 4 and C 2 H 2 /CO 2 gas separations are extremely important in the industry. Herein, a pH-stable three-dimensional (3D) metal–organic framework (MOF), IITKGP-25, possessing exposed functional sites is presented, which facilitates such separations with excellent ideal adsorbed solution theory (IAST) selectivity (4.61 for C 2 H 2 /C 2 H 4 and 3.93 for C 2 H 2 /CO 2 ) under ambient conditions (295 K, 100 kPa, 50:50 gas mixtures) and a moderate affinity toward C 2 H 2 (26.6 kJ mol –1 ). Interestingly, IITKGP-25 can maintain structural integrity in water and in aqueous acidic/alkaline (pH = 2–10) medium because of the higher coordination numbers around the metal center and the hydrophobicity of the ligand. The adsorption capacity for C 2 H 2 remains unchanged for a minimum of up to five consecutive cycles and 15 days of exposure to 97% relative humidity, which are the prerequisites of an adsorbent for practical gas separation application. Density functional theory (DFT) calculations reveal that the open Cd(II) sites and carboxylate…

The development of clean energy is one of the effective strategies to solve carbon peak and carbon neutrality. The severe recombination of photogenerated carriers is one of the fundamental reasons that hinder the development of photocatalysis. In this work, NiCo-MOF/ZIF was obtained by the “ZIF on MOF” strategy for the first time, and a stable bonding state of surface P(δ – )–Co/Ni(δ + )–O(δ – ) was formed on the surface of the catalyst by a one-step oxidation-phosphorus doping strategy. The X-ray photoelectron spectroscopy technique proves that phosphorus doping forms a unique bonding state on the surface of CoO–NiO. The novel surface bonding state can effectively inhibit the recombination of photogenerated carriers and can increase the migration rate of photogenerated electrons, which accelerates the process of photocatalytic hydrogen evolution. Photocatalytic hydrogen evolution kinetics verifies that the formation of P(δ – )–Co/Ni(δ + )–O(δ – ) bonding states can accelerate the process of photocatalytic hydrogen evolution, and the durability of the catalyst is verified by cycling…

Finding reservoir-rich and efficient bifunctional electrocatalysts for water splitting is key to further sustainable energy development. Transition metal phosphides (TMPs) are extensively exploited as effective electrocatalysts, but the construction of strong coupling interfaces to improve catalytic performance by simple methods is still a bottleneck. Here, we designed and prepared a novel heterostructure electrocatalyst composed of cobalt–molybdenum (CoMo) alloy particles integrated with CoMoP nanosheets via the method of template-assisted conversion, followed by electrodeposition. Thanks to the strong interfacial coupling and synergistic effect between CoMo alloy particles and CoMoP nanosheets, the prepared CoMo/CoMoP/NF shows outstanding activity with overpotentials of only 29 mV for the hydrogen evolution reaction (HER) and 246 mV for the oxygen evolution reaction (OER) in 1 M KOH at a current density of 10 mA cm –2 . Furthermore, the assembled CoMo/CoMoP || CoMo/CoMoP electrode can attain 10 mA cm –2 with a low battery voltage of 1.54 V. This study offers a valuable reference…

The tetravalent-state stability of manganese is of primary importance for Mn 4+ luminescence. Double perovskite-structured A 2 B′B″O 6:Mn 4+ has been recently prevalent, and the manganese ions are assumed to substitute for the B″(IV–VI)O 6 site to stabilize at the tetravalent charge state to generate far-red emissions. However, some Mn-doped A 2 B′B″O 6 -type materials show no or weak luminescence such as typical Ca 2 MgWO 6:Mn. In this work, a cation-pair co-substitution strategy is proposed to replace 2Ca 2+ by Na + –La 3+ to form Ca 2–2 x Na x La x MgWO 6:Mn. The significant structural distortion appears in the solid solution lattices with the contraction of [MgO 6 ] but enlargement of [WO 6 ] octahedron. We hypothesize that the site occupancy preference of Mn migrates from Mg 2+ to W 6+ sites. As a result, the effective Mn 4+ /Mn 2+ concentration enhances remarkably to regulate nonluminescence to highly efficient Mn 4+ -related far-red emission. The optimal CaNa 0.5 La 0.5 MgWO 6:0.9%Mn 4+ shows an internal quantum efficiency of 94% and external quantum efficiency of 82%,…

A SiO 2 @MOF core–shell microsphere for environmentally friendly applications was introduced in this study. Several types of metal–organic framework core–shell microspheres were successfully synthesized. To achieve high stability and favorable catalytic performance, modification and coating methods were necessary for optimization. The improved SiO 2 @MOF core–shell microspheres were used in the cycloaddition reaction of carbon dioxide and propylene oxide. Dispersion ability was enhanced by the addition of core–shell microspheres, which also produced high catalytic activity. Accompanied with tetrabutylammonium bromide as a co-catalyst, SiO 2 @ZIF-67 had a maximum conversion of 97%, and the results revealed that SiO 2 @ZIF-67 could be used for 5 reaction cycles while maintaining high catalytic performance. This recycling catalyst was also reacted with a series of terminal epoxides to form corresponding cyclic carbonates with high conversion rates, indicating that SiO 2 @MOF core–shell microspheres exhibit promise in the field of catalysis.

A series of two-dimensional (2D) polyoxometalate-based frameworks, [Ln 3 (PDA) 3 (H 2 O) 6 (PMo 12 O 40 )]· x H 2 O (Ln = La ( 1 ); Ce ( 2 ); Pr ( 3 ); Nd ( 4 ); PDA = 1,10-phenanthroline-2,9-dicarboxylate), have been synthesized and structurally characterized by various analytical techniques. Single-crystal X-ray diffraction reveals that 1 – 4 have a unique 2D layer structure in which Keggin anions have coordinated upward and downward the plane, and this feature makes them suitable candidates for surface binding of common drugs via supramolecular and electrostatic interactions. Also, the ability of 1 – 4 (as the first polyoxomolybdate-containing frameworks) as sorbents for the extraction and quantitative determination of opioid drugs (morphine, methadone, and pethidine) was investigated by using dispersive micro-solid-phase extraction (D-μSPE) and high-performance liquid chromatography (HPLC). The method showed wide linear ranges in the range of 0.3 to 300 ng mg –1 and low limits of detection (LODs) ranged from 0.1 to 0.2 ng mg –1 of hair.

Nanomaterials have versatile properties owing to their high surface-to-volume ratio and can thus be used in a variety of applications. This work focused on applying a facile hydrothermal strategy to prepare praseodymium vanadate nanoparticles due to the importance of nanoparticles in today’s society and the fact that their synthesis might be a challenging endeavor. The structural and morphological characterizations were carried out to confirm the influence of the optimizations on the reaction’s outcomes, which revealed praseodymium vanadate (PrVO 4 ) with a tetragonal crystal system. In this regard, the proposed development of electrochemical sensors based on the PrVO 4 nanocatalyst for the real-time detection of arsenic drug roxarsone (RXS) is a primary concern. The detection was measured by amperometric ( i – t ) signals where PrVO 4 /SPCE, as a new electrochemical sensing medium for RXS detection, increased the sensitivity of the sensor to about ∼2.5 folds compared to the previously reported ones. In the concentration range of 0.001–551.78 μM, the suggested PrVO 4 /SPCE sensor…

Non-cytotoxic upconversion nanocrystals are preferred candidates because they offer exceptional advantages for numerous applications, ranging from optical thermometry to bioimaging/biomedical applications. In this report, we demonstrate the luminescence characteristics and practical utility of a multifunctional upconversion nanophosphor based on Yb 3+ /Er 3+:La 2 (WO 4 ) 3 (LWO) flakes. Strong upconversion green emission was observed from 6-mol % Er 3+ -doped LWO nanophosphor flakes excited by a 980 nm laser. We further enhanced the upconversion emission considerably by co-doping LWO nanophosphors with Yb 3+ /Er 3+ to exploit energy migration from Yb 3+ to Er 3+ ions. The exceptional improvement in upconversion green and near-infrared emission was achieved by Yb 3+ ion co-doping up to 6 mol %; beyond 6 mol %, emission intensities remarkably dropped due to concentration quenching. Photometric parameters were evaluated with and without Yb 3+ ion-doped LWO nanophosphors, which exhibited a high green color purity of 95.6%, to elucidate their energy transfer mechanism. In addition,…