The olefin epoxidation is an essential transformation and arouses great interest among the scientific community for the key role of epoxide in the chemical industry. Traditional methods suffer from harmful...

Broad absorption spectra with efficient generation and separation of available charge carriers are indispensable requirements for promising semiconductor-based photocatalysts to achieve the ultimate goal of solar-to-fuel conversion. Here, Cu 3−x SnS 4 (x = 0-0.8) with copper vacancies have been prepared and fabricated via solvothermal process. The obtained copper vacancy materials have extended light absorption from ultraviolet to near-infrared-II region for its significant plasmonic effects. Time-resolved photoluminescence shows that the vacancies can simultaneously optimize charge carrier dynamics to boost the generation of long-lived active electrons for photocatalytic reduction. Density functional theory calculations and electrochemical characterizations further revealed that copper vacancies in Cu 3−x SnS 4 tend to enhance hydrogen's adsorption energy with an obvious decrease in its H 2 evolution reaction (HER) overpotential. Furthermore, without any loadings, the H 2 production rate was measured to be 9.5 mmol•h −1 •g −1 . The apparent quantum yield was measured to be 27% for wavelength λ > 380 nm. The solar energy conversion efficiency was measured to be 6.5% under visible-near infrared (vis-NIR) (λ > 420 nm).

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In the present study, we encapsulated sulfur with atomic vanadium (V)- and cobalt (Co)-modified Ketjen black (VCKBS) to hinder the shuttle mechanism and enhance the redox kinetics in Li–S batteries. The synthesized composite provided plenty of interfacial active sites and assured smooth electron transfer, which assisted in attaining the balance of the enhanced catalytic activity due to Co and the adsorption ability mainly derived from V. Consequently, the Li–S cells having an optimized composition presented alleviated shuttle effect, enhanced sulfur utilization and conversion efficiency, and showed stable cycling performance and an outstanding rate performance with an initial capacity of 1329 mAh g–1, which was maintained as 1249 mAh g–1 after 100 cycles. Due to impressive experimental specific capacities, the system-level specific energies and energy densities were also predicted using the 1st and 100th discharge capacities. Compared to regular Ketjen black-based cathodes, VCKBS cathodes showed 1342 and 568% improvement in the system-level energy density and specific energy based on the 100th discharge capacities, respectively. This indicates that VCKBS cathodes synthesized in a facile manner are advantageous for higher sulfur loadings at electrolyte-depleted cells and represent a viable endeavor to develop highly stable Li–S batteries.

Electroreduction of CO 2 powered by renewable energy has been proposed to realize carbon neutrality as a response to subsequent global warming. However, these strategies either suffer from low efficiency and spatial and temporal limitations or require a large amount of energy and CO 2 gas of high purity. These shortcomings can be addressed by the development of a green, renewable electrochemical system that directly fixes atmospheric CO 2 to generate biomass chemicals. Here, we present a flow electrochemical microbial CO 2 fixation system (EMCF) based on the propagation of Acidithiobacillus ferrooxidans in the presence of Fe 2+ /Fe 3+ as redox mediators. We demonstrate that the overpotential is significantly reduced by the in situformed Fe 2 CoSe 4 electrocatalysts, which results in an energy consumption of 15.6 GJ per ton fixed CO 2 when paired with the oxygen evolution reaction. We show that the energy consumption can be reduced to 0.62 GJ/t when KI is used for selective 5hydroxymethylfurfural oxidation and can even supply an energy of 10.08 GJ/t at low current density. This study demonstrates that the proposed EMCF system has the potential to be a sustainable and carbon-negative platform that can convert atmospheric CO 2 into value-added biomass chemicals and realize the selective oxidation of a broad range of chemicals simultaneously.