Hierarchical Heterometallic Sulfur/Selenide Electrocatalysts Derived from Polyoxometalate for Enhanced Hydrogen Production Performance

The hydrogen evolution reaction (HER) holds significant importance in the process of hydrogen generation through water electrolysis. Currently, there is a pressing requirement to develop highly effective electrocatalysts to enhance HER rates and facilitate practical hydrogen production. A composite MoS2/CoS2@Ni3S2/Ni3Se2 was fabricated by using (C3H5N2)6[CoIIMo12O40]·10H2O (CoMo12) as the metal source, thioacetamide as the sulfur source, and nickel foam as both the nickel source and matrix. The fabrication process involved hydrothermal vulcanization and selenization stepwise assembly procedures. When evaluating the catalytically resolved water reaction for MoS2/CoS2@Ni3S2/Ni3Se2 in a 1.0 M potassium hydroxide (KOH) electrolyte, the measured overpotential was 56 mV when the current density was 10 mA cm–2. The value was close to the overpotential of a Pt electrode (35 mV). Furthermore, X-ray diffraction analyses performed both before and after the catalytic reaction, along with a 24 h stability assessment, provided unequivocal evidence of the outstanding stability of the electrode in 1.0 M KOH. Overall, the MoS2/CoS2@Ni3S2/Ni3Se2 composite ranks among the most valuable nonprecious metal catalysts for the HER reported so far. The successful synthesis of MoS2/CoS2@Ni3S2/Ni3Se2 presented in this study introduces a novel approach for creating highly efficient, nonprecious metal electrocatalysts.