Well-shaped Cu 2 O nanocubes (NCs) are synthesized under mild conditions, and they exhibit robust laccase-mimicking activity, enabling versatile environmental and biomedical applications.

Developing low-cost, high-efficiency oxygen evolution reaction electrocatalysts is crucial for sustainable green hydrogen production via water electrolysis. Nonetheless, complex synthetic processes, low catalytic activity, and limited durability of catalysts pose significant challenges for industrial-scale applications, particularly in seawater electrolysis, where Cl--induced chlorine oxidation and electrode corrosion are prominent issues. In this work, we present a one-step hydrothermal method to fabricate NiFe layered double hydroxide@Fe-doped nickel sulfide nanohybrids on nickel foam (NiFe LDH@NixFe3-xS2/NF) using sodium thiosulfate as a dual-function precursor (decomposing to S2- for sulfide formation and SO42- for LDH modification). The optimal catalyst demonstrates exceptional OER performance in alkaline freshwater (1 M KOH) with overpotentials of 191, 229, and 272 mV to achieve 10, 100, and 500 mA cm-2, respectively, alongside a low Tafel slope of 34.5 mV dec-1, while maintaining stability for 530 h at 500 mA cm-2. In alkaline simulated seawater, it shows comparable activity (197/240/306 mV at the same current densities). Additionally, the self-assembled Pt/C/NF||NiFe LDH@NixFe3-xS2-2/NF couple delivers 10 mA cm-2 at 1.520 V for overall water splitting in an alkaline saline electrolyte. The enhanced performance is attributed to synergistic effects of hydroxide/sulfide nanointerfaces, low interfacial resistance, SO42--mediated Cl- repulsion/OOH* stabilization, and active β-NiOOH formation, underscoring its potential for practical seawater-based green hydrogen production.

Electrochemical water splitting for hydrogen production is often impeded by the sluggish kinetics of the oxygen evolution reaction at the anode. Therefore, developing efficient, stable, and cost-effective electrocatalysts to accelerate this reaction is imperative. In this study, we adopted a surface engineering strategy using sodium 3aminobenzenesulfonate as a structure-directing agent to fabricate hierarchically micro-nanostructured nickeliron layered double hydroxides/beta-nickel oxyhydroxides (NiFe LDH/beta-NiOOH) via a one-step hydrothermal method. This approach led to the formation of a unique hierarchical structure, featured by numerous nanosheet arrays in-situ grown on microplates, which endowed the material with abundant active sites. The synergistic effect of NiFe LDH and beta-NiOOH species enhanced both intrinsic activity and durability. Furthermore, the intercalated 3-aminobenzenesulfonate anions can serve as proton acceptors, enhancing deprotonation capabilities and thereby accelerating the OER kinetics. The optimized sample displayed the overpotentials of 226 and 277 mV at current densities of 10 and 100 mA cm-2 respectively, along with a small Tafel slope of 36.0 mV dec-1. More impressively, after 200 h of durability operation at a fixed potential, the current density notably increased by approximately 20%, rising from 100 mA cm-2 to 120 mA cm-2, possibly relative to the selfexfoliation of thicker microplates into fewer-layered structures, which continuously exposed new active sites and significantly mitigated stability degradation caused by metal dissolution.

The electrochemical oxygen evolution reaction (OER) holds paramount significance as a pivotal stage within electrochemical water-splitting processes, particularly in hydrogen production. Highly efficient OER electrocatalysts with inherent capability to effectively lower the energy barrier and promote fast kinetics are in high demand. In this research, we have introduced a novel strategy of modifying the non-precious metal benchmark catalyst, NiFe layered double hydroxide (LDH), through multiple oxyanions. Our approach involved incorporating MoS42- as a source of modified anions to enhance the performance of LDH in OER. Under specific conditions of the hydrothermal reaction, a majority of the sulfur (S) within the MoS42- anions underwent oxidization, resulting in the formation of SO42- and MoOxS4-x2 groups. As a result, NiFe LDH composites that were modified with multiple oxyanionic moieties, were successfully fabricated. Thanks to the synergistic effects of these oxyanions, which accelerate the generation of active NiOOH species, the optimized NiFe LDH-MoS4-0.1/NF sample exhibited a significantly low overpotential of 228 and 270 mV at current densities of 10 and 100 mA cm(-2), respectively, along with a low Tafel slope of 35.5 mVdec(-1) in 1 M KOH electrolyte solution. Our study underscored the importance of embracing diverse oxyanions modification strategy to amplify the performance of OER, opening up numerous opportunities for energy conversion and storage applications.

The oxygen evolution reaction (OER), a crucial semireaction in water electrolysis and rechargeable metal-air batteries, is vital for carbon neutrality. Hindered by a slow proton-coupled electron transfer, an efficient catalyst activating the formation of an O-H bond is essential. Here, we proposed a straightforward one-step hydrothermal procedure for fabricating PO43--modified NiFe layered double-hydroxide (NiFe LDH) catalysts and investigated the role of PO43- anions in enhancing OER. Phosphate amounts can efficiently regulate LDH morphology, crystallinity, composition, and electronic configuration. The optimized sample showed a low overpotential of 267 mV at 10 mA cm-2. Density functional theory calculations revealed that intercalated and surface-adsorbed PO43- anions in NiFe LDH reduced the Gibbs free energy in the rate-determining step of *OOH formation, balancing oxygen-containing intermediate adsorption/dissociation and promoting the OER. Intercalated phosphate ions accelerated precatalyst dehydrogenation kinetics, leading to a rapid reconstruction into active NiFe oxyhydroxide species. Surface-adsorbed PO43- interacted favorably with adsorbed *OOH on the active Ni sites, stabilizing *OOH. Overall, the synergistic effects of intercalated and surface-adsorbed PO43- anions significantly contributed to enhanced OER activity. Achieving optimal catalytic activity requires a delicate equilibrium between thermodynamic and kinetic factors by meticulously regulating the quantity of introduced PO43- ions. This endeavor will facilitate a deeper comprehension of the influence of anions in electrocatalysis for OER.

Catalytic oxidation of alcohols to their correspondingaldehydesand ketones plays a fundamental role in many industries, but conventionalstrategies suffer from high costs, harsh reaction conditions, andlow energy efficiency. Here, we combine the p-xylyleneglycol oxidation with the hydrogen evolution reaction via an I-/I-3 (-) redox mediator inan electrochemical flow system where inexpensive graphite felt (GF)is utilized as electrodes. In comparison to traditional chemical oxidation,the electrochemical flow synthesis via the mediator I-/I-3 (-) could offer an outstanding p-hydroxymethyl benzaldehyde selectivity of 96.5% and aFaradaic efficiency of 84.8%. Besides, we realize the gram-scale synthesisof p-hydroxymethyl benzaldehyde at the current densityof 25 mA/cm(2) with low energy consumption because of theprepared catalytically efficient GF-Cu7S4 andGF-Pt electrodes. We explore different substrates and observe theflexible adaptability of our proposed flow synthesis strategy, demonstratingits potential for industrial applications. An electrochemical flow synthesis strategyis proposed hereinfor the gram-scale synthesis of p-hydroxymethyl benzaldehydewith low energy consumption.

Developing a cost-saving, high-efficiency, and simple synthesis of counter electrode (CE) material to replace pricy Pt for dye-sensitized solar cells (DSSCs) has become a research hotspot. Owing to the electronic coupling effects between various components, semiconductor heterostructures can significantly enhance the catalytic performance and endurance of counter electrodes. However, the strategy to controllably synthesize the same element in several phase heterostructures used as the CE in DSSCs is still absent. Here, we fabricate well-defined CoS2 /CoS heterostructures and use them as CE catalysts in DSSCs. The as-designed CoS2 /CoS heterostructures display high catalytic performance and endurance for the triiodide reduction in DSSCs thanks to the combined and synergistic effects. As a result, a DSSC with CoS2 /CoS achieves a high energy conversion with an efficiency of 9.47 % under standard simulated solar radiation, surpassing that of pristine Pt-based CE (9.20 %). Besides, the CoS2 /CoS heterostructures possess a quick activity initiation process and extended stability, broadening their potential applications in various areas. Therefore, our proposed synthetic approach could offer new insights for synthesizing functional heterostructure materials with improved catalytic activities in DSSCs.

Oxygen evolution reaction (OER) is an essential process during electrochemical water -splitting. Due to its sluggish kinetics, low cost and highly efficient catalyst is invariably desired to decrease its overpotential for large-scale application. However, the overpotential of most advanced OER electrocatalysts is still more than 200 mV at the current density of 10 mA cm-2. In this work, we constructed active layered NiFe double hydroxides with cation defects on self-supported three-dimensional (3D) CoNi nitrogen-doped carbon nanotube composite substrate as integrated OER catalyst. Strikingly, electrochemical measurements showed that the optimized sample exhibited outstanding OER activity with low overpotentials of 178 and 268 mV at the current densities of 10 and 100 mA cm-2 in alkaline environment, alongside a good durability. The excellent OER performance was ascribed to the strongly synergistic effect of intrinsically active NiFe double hydroxide layers with abundant cation vacancies and 3D carbon nanotube composite substrate with good conductivity and various functional moieties, thus facilitating the electrocatalytic kinetic.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Three new coordination polymers based on V-shaped ligands, namely {[Cd(BIDPS)(PA)(H2O)]center dot CH3OH}(n)(1), {[Zn(BIDPS)(p-bdc)]center dot H2O}(n) (2) and [Mn(BIDPT)(NBA)](n) (3) (BIDPS=4,4'-bis(imidazol-l-yl)-phenyl sulphone, H(2)PA=pamoic acid, p-H(2)bdc=p-phthalic acid, BIDPT=4,4'-bis(imidazol-l-yl)diphenyl thioether, H(2)NBA= 4,4'-azanediyl dibenzoic acid) have been hydrothermally synthesized and structurally characterized. Compounds 1 and 2 feature an undulate 2D layer structure. Compound 1 exhibits a rare 2D -> 3D inclined polycatenated structure, while compound 2 is further joined by intermolecular hydrogen bondings to form a 3D network. Compound 3 displays a 3-connected hexagonal layer hcb topology (honeycomb network) and is further assembled into a 3D network via C-H center dot center dot center dot pi interaction. Compounds 1 and 2 showed excellent water stability and fluorescence, which were further confirmed as bifunctional fluorescent sensors for Fe3+ and Cr2O72- with high selectivity, sensitivity, and anti-interference ability in the water. The mechanisms of fluorescence quenching were also studied in detail. CCDC: 1919698, 1; 2085947, 2; 2117923, 3.

A cuprous cluster-based luminescent coordination polymer [Cu(OPY)Cl](n) (1, OPY = 4,4'-(oxybis (4,1-phenylene))dipyridine) has been hydrothermally synthesized and structurally characterized. Compound 1 consists of bent butterfly dinuclear [Cu2Cl2] core and V-shaped OPY ligand, which exhibits a perpendicularly interpenetrated 2D + 2D -> 3D structural characteristic. Compound 1 emits orange red luminescence originated from the dual-emitting behavior at room temperature in the solid state. Its photoluminescence properties have been fully studied and verified by time-dependent density functional theory (TD-DFT) calculations. In addition, the grinding and temperature dependent luminescence properties of 1 have also been investigated in detail.

Three new coordination polymers based on V-shaped ligands,namely{[Cd(BIDPS)(PA)(H2O)]·CH3OH}n(1),([Zn(BIDPS)(p-bdc)]·H2O}n(2)and[Mn(BIDPT)(NBA)]n(3)(BIDPS=4,4'-bis(imidazol-l-yl)-phenyl sulphone,H2PA=pamoic acid,p-H2bdc=p-phthalic acid,BIDPT=4,4'-bis(imidazol-l-yl)diphenyl thioether,H2NBA=4,4'-azanediyl dibenzoic acid)have been hydrothermally synthesized and structurally characterized.Compounds 1 and 2 feature an undulate 2D layer structure.Compound 1 exhibits a rare 2D→3D inclined polycatenated structure,while compound 2 is further joined by intermolecular hydrogen bondings to form a 3D network.Compound 3 displays a 3-connected hexagonal layer hcb topology(honeycomb network)and is further assembled into a 3D network via C—H…π interaction.Compounds 1 and 2 showed excellent water stability and fluorescence,which were further con-firmed as bifunctional fluorescent sensors for Fe3+and Cr2O72-with high selectivity,sensitivity,and anti-interference ability in the water.The mechanisms of fluorescence quenching were also studied in detail.CCDC:1919698,1;2085947,2;2117923,3.

Three Zn.. -based metal-organic frameworks with V-shaped ligands, namely {[Zn-2(BIDPS)(2)(OBA)(2)]center dot DMA}(n)(1), {[Zn(BIDPT)(PA)]center dot DMF}(n) (2), and {[Zn(BIDPS)(PA)(H2O)(2)] center dot 2H(2)O}(n) (3) ( BIDPS = 4,4'-bis(imidazol-l-yl) -phenyl sulphone, H(2)OBA= 4,4'-oxybisbenzoic acid, H(2)PA=pamoic acid, BIDPT=4,4' -bis(imidazol-l-yl)diphenyl thioether), have been hydrothermally synthesized and characterized by single X-ray diffraction, IR spectroscopy, thermogravimetric analysis, and powder X-ray diffraction. Compound 1 shows a two-fold 3D network with cds topology. Compound 2 is a 2D (4,4) layer network and shows a 2D -> 3D parallel-parallel polycatenation framework. Compound 3 exhibits an infinite chain, and such 1D chains are further interlinked into a 3D supramolecular structure via intermolecular and intramolecular hydrogen bonds. Compounds 1-3 could stably exist in aqueous solutions with pH=4-10. Compounds 1-3 demonstrated strong luminescence in aqueous solution, and fluorescence studies show that 1-3 could detect 2,4,6-trinitrophenol and Fe3+ with high sensitivity and selectivity by luminescent sensing. CCDC: 2129934, 1; 2129682, 2; 2129683, 3.

A binder-free and self-supported 3D carbon nanotube composite electrode with NiFe nanoalloys, N doping and Fe/Ni-N x -C structures was fabricated by a facile method. The strong synergistic effects of multi-components and the unique structural merits of the optimized sample endowed it outstanding oxygen reduction reaction activity with an onset potential of 1.048 V vs. RHE in 0.1 M KOH solution.

Mesoporous core-shell structure Ag@SiO2 nanospheres are constructed to prevent Ag nanoparticles from aggregation during the hydrogenation reaction. The prepared catalyst shows superior catalytic performance for hydrogenation of nitro compounds with 100% conversion and selectivity without any by-products, which also indicates good recycling performance for several times use.

The sluggish kinetics of oxygen reduction reaction (ORR) has severely impeded the application of fuel cell technology. Developing economical and efficient biomass-based catalysts derived from natural waste to replace the expensive noble metal catalysts is becoming an attractive strategy. However, biomass materials often have geographical and seasonal characteristics. Thus, developing diversified and available biomass-derived catalysts is significant for different regions. In this work, N, P-dual doped porous carbon materials derived from waste lotus seedpod with tunable specific surface areas and porous structure are skillfully fabricated. The optimized sample exhibits excellent oxygen reduction reaction activity with an onset potential of 0.87 V vs. RHE and a Tafel slope of 81 mV dec−1, showing the 4e‒ electrons transfer path in alkaline solution. It also exhibits much better stability and methanol tolerance than commercial Pt/C. High ORR performance is considered to be ascribed to the abundant N, P dispersion and the hierarchical porous structure.

A new Cu(II) coordination polymer, {[Cu-3(oba)(2)(mu(3)-OH)(2)(H2O)(2)]center dot 6H(2)O}(n) (H(2)oba = 4,4'-oxydibenzoic acid), was synthesized by the solvothermal route and characterized by IR, TGA and XRD. The complex crystallizes in the monoclinic system, space group P2(1)/c with a = 5.957(6), b = 29.746(3), c = 9.351(7) angstrom, beta = 125.709(4)degrees, V = 1345.4(2) angstrom(3), Z = 2, C28H36Cu3O20, M-r = 883.09, D-c = 1.913 g/cm(3), F(000) = 782, mu = 2.427 mm(-1), R = 0.0780 and wR = 0.1688 for 3120 observed reflections with I > 2 sigma (I). The complex forms a 3D framework based on rare infinite rod-shaped secondary building units (SBUs), and C-H center dot center dot center dot pi interactions play an important role in stabilizing the 3D supramolecular architecture. It shows excellent catalytic activities for the degradation of safranin O (SO) and methylene blue (MB) dyes in aqueous solution under UV light irradiation. Furthermore, the apparent rate constants have also been investigated.

Oxygen evolution reaction (OER) is regarded as a limit-efficiency process in electrochemical water splitting generally, which needs to develop the effective and low-cost non-noble metal electrocatalysts. Oxygen vacancies have been verified to be beneficial to enhance the electrocatalytic performance of catalysts. Herein, we report the facile synthesis of reduced CoFe2O4/graphene (r-CFO/rGO) composite with rich oxygen vacancies by a citric acid assisted sol- gel method, heat treatment process and the sodium borohydride (NaBH4) reduction. The introduction of graphene and freezing dry technique prevents the restacking of GO and the aggregation of CFO nanoparticles (NPs) and increases the electronic conductivity of the catalyst. Fast heating rate and low anneal temperature favors to obtain low crystallinity and lattice defects for CFO. NaBH4 reduction treatment further creates the rich oxygen vacancies and electrocatalytic active sites. The obtained r-CFO/rGO with high specific surface area (108 m(2) g(-1)), low crystallinity and rich oxygen vacancies demonstrates a superior electrocatalytic activity with the smaller Tafel slope (68 mV decb(-1)), lower overpotential (300 mV) at the current density of 10 mA cm(-2), and higher durability compared with the commercial RuO2 catalyst. This green, low-cost method can be extended to fabricate similar composites with rich defects for wide applications. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

A new dinuclear Co(II) coordination compound [Co-2(DPFE)(oba(2-))(2)]n (1) has been solvothermally synthesized from rigid DPFE ligand and V-shaped polycarboxylate acid H(2)oba [DPFE = 2,7-di(pyridin-4-yl)-9H-fluorene, H(2)oba = 4,4'-oxydibenzoic acid]. Compound 1 presents a 2-fold interpenetrated 3D framework containing righthanded helical chains. Magnetic measurements performed on 1 indicate the occurrence of antiferromagnetic interactions among the adjacent Co(II) ions.

Developing valid strategies to fabricate highly active non-platinum-group metal electrocatalysts for catalyzing the sluggish cathode oxygen reduction reaction (ORR) is urgently required. To our knowledge, the catalytic performance of heterogeneous catalysts is highly related to their electronic and architectural properties. Defect or vacancy engineering is a particularly attractive means of modifying the physicochemical properties of nanomaterials. Herein, in this work, we proposed a facile Zn-induced defect strategy to engineer the electronic and surface structure of non-noble bimetallic NiCo alloy@nitrogen-doped graphene hybrid nanomaterials for boosting ORR activity. The optimized sample shows prominently enhanced activity for the ORR in KOH solution and exhibits better stability and methanol tolerance compared to Pt/C. Physicochemical and electrochemical measurements demonstrate that the enhanced ORR performance is mainly ascribed to the proper Zn-induced vacancy defects, which finely modulate the energy level of electrocatalyst, thus activating ORR process thermodynamically. Moreover, rich exposed active sites from vacancy defects largely facilitate the sluggish kinetics. This strategy is exceptionally promising to be applied to optimize other non-noble metal-based nanomaterials for highly efficient electrocatalysis.

A simple and facile sol-gel method was used to fabricate novel uniform silica nanotubes and hollow spheres controllably in the same reaction system. The different reaction conditions were investigated, such as reaction time, addition and stirring rate of tetraethyl orthosilicate (TEOS) and the ratio of water and ethanol, which had important influence on the formation of the silica nanotubes with uniform morphologies. The formation process investigation of silica nanotubes discloses that ammonium citrate (AC) crystals have the thin pillar-like morphologies in the mixed solution including ethanol and water, which acts as an important template for the gradual aggradation of silica colloids on their surface to form the tubular structure. The silica hollow spheres have the similar formation mechanism to that of silica nanotubes with a little difference of using citric acid (CA) as a starting structure-directing agent.