Search

Hydrogen (H2) is a new type of renewable energy that can meet people's growing energy needs and is environmentally friendly. In order to improve the industrial application prospects and electrochemical performance of hydrogen evolution catalysts, extensive research on transition metal materials has been carried out. Among the many catalytic materials, cobalt is an element with potential for the hydrogen evolution reaction (HER) due to its abundant reserves, low cost, and small energy barrier for H adsorption. This review classifies the latest research on cobalt-based catalysts according to the types of compound, including cobalt-based sulfides, phosphides, carbides, borides, oxides, etc., and summarizes the latest research progress of cobalt-based compound catalysts in acidic and alkaline media. Strategies to tune the properties of cobalt-based compound catalysts for high catalytic activity for HER are focused on, including structural engineering, defect engineering, and doping, etc. The advantages and limitations of each modified approach are reviewed. Not only that, but also the catalytic activity and advantages of the catalyst are evaluated by using density functional theory (DFT) calculation-related descriptors, activity evaluation parameters, etc. Finally, limitations and challenges of cobalt-based materials for HER are presented, as well as prospects for future research. This paper aims to understand the chemical and physical factors that affect cobalt-based catalysts, and to find directions for future research on cobalt-based catalysts. [ABSTRACT FROM AUTHOR]

In this paper, we present a MoP/P–Mn0.5Cd0.5S photocatalytic material (PMOMCS-Px). A novel catalyst can efficiently split water into hydrogen without precious metals. In the sacrificial agent environment, the HER (hydrogen evolution rate) of PMOMCS-P5 was 4368.25 μmol g−1 h−1 which was 11.4 times greater than the HER of Mn0.5Cd0.5S (383.19 μmol g−1 h−1), and its hydrogen production performance was better than that of Pt/Mn0.5Cd0.5S (2.0 wt% Pt). Furthermore, the hydrogen evolution performance of PMOMCS-P5 under pure water conditions was also examined, and the HER of PMOMCS-P5 was 209.76 μmol g−1 h−1, which was 20.4 times that of Mn0.5Cd0.5S (10.29 μmol g−1 h−1). Its characterization proved that the introduction of the co-catalyst MoP and P doping inhibited the recombination of e− and h+, enhanced the reduction capacity, and reduced the hydrogen precipitation reaction overpotential of PMOMCS-Px, thus enhancing the hydrogen production performance of PMOMCS-Px. Therefore, an efficient and economical photocatalyst was prepared. [ABSTRACT FROM AUTHOR]

Metal halide perovskites, such as iodine methylamine lead (MAPbI3), have received extensive attention in the field of photocatalytic decomposition of HI for hydrogen evolution, due to their excellent photoelectric properties. In this paper, a new MAPbI3-based composite, MoC/MAPbI3, was synthesized. The results show that 15 wt% MoC/MAPbI3 has the best hydrogen production performance (38.4 μmol h−1), which is approximately 24-times that of pure MAPbI3 (1.61 μmol h−1). With the extension of the catalytic time, the hydrogen production rate of MoC/MAPbI3 reached 165.3 μmol h−1 after 16 h due to the effective separation and transfer of charge carriers between MoC and MAPbI3, showing excellent hydrogen evolution rate performance under visible light. In addition, the cycling stability of MoC/MAPbI3 did not decrease in multiple 4 h cycle tests. This study used the non-precious metal promoter MoC to modify MAPbI3, and provides a new idea for the synthesis of efficient MAPbI3-based composite catalysts. [ABSTRACT FROM AUTHOR]