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To overcome the inherent drawbacks of traditional solid-phase synthesis methods, this paper reported an in situ solid-phase synthesis method for preparing NiCo2Se4/carbon nanotube (NiCo2Se4/CNT) nanocomposite. By this method, NiCo2Se4 nanospheres are loaded onto the surface and inside the 3D conductive framework constructed by CNTs. This unique morphology provides conductivity and structural stability to the synthesized nanocomposite, resulting in good rate capability and cycling performance in both hybrid supercapacitor and sodium-ion battery applications. The hybrid supercapacitor device based on the synthesized nanocomposite can deliver an energy density of 33.32 Wh kg–1 at a power density of 0.844 kW kg–1 while retaining 67.5% of energy density at a high power density of 11.73 kW kg–1. After 20 000 cycles, the energy density still reaches 91.6% of that in the initial cycle. When employed as an anode material for SIBs, the synthesized nanocomposite exhibits a high reversible specific capacity of 367.1 mAh g–1 with a Coulombic efficiency of 99.27% after 300 cycles at 0.1 A g–1, while 91.3% of the specific capacity is retained as the current density rises from 0.1 to 3 A g–1. After 500 cycles at a current density of 2.0 A g–1, the reversible specific capacity of the synthesized nanocomposite reaches 319 mAh g–1 with a very low specific capacity attenuation of 0.021% per cycle. The developed method contributes to reducing the cost of preparing TMSe-based electrode materials while achieving high performance, thus boosting its application in electrochemical energy storage systems. [ABSTRACT FROM AUTHOR]

The photoelectrochemical (PEC) reduction of CO2 into organic chemicals on the semiconductor is considered a feasible plan to address the global energy crisis and climate warming. Herein, the heterojunctions NiMoO4/ZnO-x are designed and synthesized. The nanosheets of NiMoO4 have excellent absorption of photons and benefit the C–C coupling to C2 compounds. The ZnO/C core fabricated from MOF rich in CN species harvests light to generate a lot of thermal electrons assisting CO2 reduction. Benefitting from its unique chemical properties and structure, the as-prepared NiMoO4/ZnO-3 heterojunction exhibited impressive performance in CO2 reduction, yielding oxygenated chemicals with 72.6% selectivity for C2 products at a rate of 29.2 μM cm−2 h−1. The formation rate under photoelectrochemical conduction is three times that of photocatalysis plus electrocatalysis, showing a strong synergetic effect of photo- and electro-catalysis. The isotopic labeling experiments of 13CO2 verified that the products are derived from CO2 and water. Finally, a new catalytic mechanism with bimetallic centers is proposed firstly to explain the reaction pathways with high selectivity of C2 chemicals. The important intermediates and the C–C coupling via Ni–Mo bicentre are proven by density-functional theory (DFT) calculations and verified by operando Fourier transform infrared (FTIR) spectrometry. On the other hand, the effect of thermal electrons is investigated as well. [ABSTRACT FROM AUTHOR]

Malate dehydrogenase (MDH) ubiquitously exists in living organisms and has many isoforms in a single species. MDHs from some classes have been characterized for their catalytic properties, which show significant variations despite that they share high sequence identity for the active sites. One class MDH, the plastid-localized NAD-dependent MDH (plNAD-MDH) is known to be important for plant survival in a dark environment, but its biochemical and enzymatic properties have not been well characterized. This study attempts to fill the gap. plNAD-MDH was expressed in an Escherichia coli system and purified using nickel-affinity chromatography followed by size exclusion chromatography. The N-terminal fusion his-tag was removed by protease cleavage. The gel filtration assay and glutaraldehyde cross-linking results showed that the active enzyme was a homodimer in solution. Further assay indicated that plNAD-MDH is most active at a neutral pH value. The Km values for oxaloacetate and NADH are found in the submillimolar order, a median range for most MDHs. The maximum reaction rate values, however, are dramatically different from other plant MDHs, indicating that plNAD-MDH has different substrate specificity. Moreover, we obtained crystals for this enzyme, which laid the groundwork for further analysis of the enzymatic mechanism from structural stand point. [ABSTRACT FROM AUTHOR]

Semiconductors, such as metal oxides and metal sulfides (MS X ), are widely investigated as effectively catalytic materials to convert carbon dioxide (CO 2 ) and water into chemicals under simulated solar light. These valuable investigations might address both the energy crisis and climate change in our modern society. Herein, a novel strategy to construct leaf-like heterojunctions of V S -ZnIn 2 S 4 /TiN-x is reported. The new semiconductor heterojunctions were then applied to photoelectrocatalytic CO 2 reduction, achieving excellent performance (formate formation rate of 1173.2 μM h -1  cm -2 ) attributed to the plant cell-like morphology and enhanced electron mobility from the heterojunction interfaces to the active sites on the surface. Our findings suggest that titanium nitride (TiN) with good conductivity can improve the photoelectrocatalytic ability of MS X through heterojunction construction. The photocathode V S -ZnIn 2 S 4 /TiN-3 exhibits 81.0 % selectivity toward C2 products by optimizing the material structure and reaction conditions. According to the systematic investigation of operando Fourier transform infrared (FTIR) spectra, common intermediates such as *COO - , *COOH, *CO, *CHO, *COCHO, and *COCH 3 reported in the literature were carefully verified. Among these, the carbene specie serve as the key intermediate responsible for generating other intermediates and resulting in all products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The production of H 2 from water using photocatalysts is a promising way of generating clean, renewable and alternative energy. The key issue is to develop active and stable photocatalysts. Here, we report a novel CdS/Pt/Mo 2 C heterostructure photocatalyst, where Pt nanoparticles are closely supported on CdS/Mo 2 C. The UV-vis spectrum and EIS Nyquist plots show that Mo 2 C can boost the absorption in the UV-vis region and improve the separation of the photogenerated electron-hole pairs from CdS. The Pt nanoparticles act as the active co-catalyst that promotes the transient photocurrent response. As a result, the CdS/Pt/Mo 2 C photocatalyst exhibits an excellent H 2 evolution activity up to 1828.82 μmol h -1 g -1 under visible-light irradiation, 8.5 and 16.2 times higher than that of pristine CdS and CdS/Mo 2 C, respectively. Moreover, a high apparent quantum yield (AQY) of 9.39% is obtained at 400 nm for the CdS/Pt/Mo 2 C heterostructure photocatalyst., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)