Ultralow-temperature assisted synthesis of single platinum atoms anchored on carbon nanotubes for efficiently electrocatalytic acidic hydrogen evolution

Although platinum(Pt) is highly active for hydrogen evolution reaction(HER)[1], it is crucial to explore the effective approach for minimizing the Pt loading amount in the practical application. Herein, one ultralow-temperature solution reduction approach is developed to anchor atomically dispersed Pt atoms on carbon nanotubes(Pt-CNTs), which decelerates the diffusion rate of Pt Cl2-6 ion reached onto the carbon nanotubes and lowers the free energy of Pt atoms in the solution to reduce the probability of the Pt aggregation. The obtained Pt-CNTs exhibits a low overpotential of 41 mV@10 mA cm^(-2) for HER in acidic media. The calculation results revealed that the improvement of the electrocatalytic activity is contributed by the interaction between CNTs and Pt atoms, which descreases the the Pt d band cneter referred to the Fermi level and lowers the Gibbs free energy of H*adsorption. This work may provide one easy and convenient strategy for the large-scale use of Pt catalysts in practical applications.

In situ photocatalytically enhanced thermogalvanic cells for electricity and hydrogen production

Converting low-grade thermal energy into electricity through ther-mogalvanic cells offers a promising approach to addressing environ-mental challenges[1].However,thermogalvanic cells face obstacles,due to limited thermopower,connected to differences in solvent-dependent entropy(ΔS)among redox anions and varying concentration ratios(ΔC)between hot and cold sides[2,3].A typical strategy to enhance the thermopower involves the improvement ofΔS of the redox anions.Un-fortunately,ΔC tends to approach zero spontaneously due to the ther-modynamic instability and redox ion diffusion.Thus,the challenge is to maintain significantΔC for both redox ions and unravel the intricate modulation mechanisms[4].

High efficiency and selectivity catalyst for photocatalytic oxidative coupling of methane

Methane(CH_(4))holds great promise in replacing oil as a building block for chemical commodities[1].However,due to the low-polar nature and high C-H bond energy(439 kJ/mol)of CH_(4),the conversion of CH_(4)by traditional thermocatalysis requires harsh reaction conditions(e.g.high temperature and high pressure)and thus,is energy-consuming[2].To be worse,the production of undesired products like CO_(2)is unavoidable as a result of hydrocarbon combustion reactions[2].

WO_(3)@Fe_(2)O_(3) Core-Shell Heterojunction Photoanodes for Efficient Photoelectrochemical Water Splitting

Photoelectrochemical(PEC) hydrogen production from water splitting is a green technology to convert solar energy into renewable hydrogen fuel. The construction of host/guest architecture in semiconductor photoanodes has been proven to be an effective strategy to improve solar-to-fuel conversion efficiency. In this study, WO_(3)@Fe_(2)O_(3) core-shell nanoarray heterojunction photoanodes are synthesized from the in-situ decomposition of WO_(3)@Prussian blue(WO_(3)@PB) and then used as host/guest photoanodes for photoelectrochemical water splitting, during which Fe_(2)O_(3) serves as guest material to absorb visible solar light and WO_(3) can act as host scaffolds to collect electrons at the contact. The prepared WO_(3)@Fe_(2)O_(3) shows the enhanced photocurrent density of 1.26 m A cm^(-2)(under visible light) at 1.23 V. vs RHE and a superior IPEC of 24.4% at 350 nm, which is higher than that of WO_(3)@PB and pure WO_(3)(0.43 m A/cm^(-2) and 16.3%, 0.18 m A/cm^(-2) and 11.5%) respectively, owing to the efficient light-harvesting from Fe_(2)O_(3) and the enhanced electron-hole pairs separation from the formation of type-Ⅱ heterojunctions, and the direct and ordered charge transport channels from the one-dimensional(1D) WO_(3) nanoarray nanostructures. Therefore, this work provides an alternative insight into the construction of sustainable and cost-effective photoanodes to enhance the efficiency of the solar-driven water splitting.