Directed synthesis of synergistic trimetallic sulfides hydrogen evolution electrocatalysts by pre-designed polynuclear silver modified POMCPs

Electrocatalytic water splitting offers a simple, efficient, and environmentally friendly method for sustainable hydrogen production. Therefore, in this study, transition metals were introduced into polyoxometalate-based coordination polymers (POMCPs) to form a novel highly efficient and stable trimetallic sulfide material. The POMCPs [Ag(C₂H₂N₃)]₃(PMo₁₂O₄₀)·3H₂O (1) was served as molybdenum and silver sources, while thiourea provided sulfur source, respectively, and nickel foam was utilized both as a three-dimensional conductive substrate and a nickel source, and a uniform growth of MoS₂/Ag₂S/NiS@NF trimetallic sulfide was prepared by one-step hydrothermal method. This approach not only takes advantage of the strong electronic coupling between Ag₂S and MoS₂ matrix, but also creates a large number of interfacial defects or strong electronic interactions. The electrocatalytic performance of MoS₂/Ag₂S/NiS@NF outperformed many polyoxometalate-based and sulfide-based catalysts, demonstrating a low overpotential of 100 mV and a Tafel slope of 100 mV dec⁻¹ at a current density of 10 mA cm⁻². The Faraday efficiency of the composite can reach 96.5%. The synergistic effects and enhanced electron transfer occurring at the interfaces of the sulfide heterostructures facilitate the increase of active sites and significantly improve the electrocatalytic properties of the material. This work provides a promising approach for the design and fabrication of highly efficient trimetallic sulfide electrocatalysts.