Interface-assisted phase transition in MOF-derived MoS2/CoS2 heterostructures for highly efficient dual-pH hydrogen evolution and overall water splitting

Abstract

Fine regulation of the interface phase and electronic structure is crucial for the hydrogen evolution reaction (HER) in low-cost heterogeneous catalysts. Herein, we have successfully synthesized MoS₂/CoS₂ hetero-nanostructures with an abundant 1T-MoS₂ phase on a cobalt metal–organic framework (MOF), which show superior HER activity and stability with quite low overpotentials of 37 and 51 mV at 10 mA cm⁻², and small Tafel slopes of 46 and 45 mV dec⁻¹ in alkaline and acidic media, respectively, outperforming most of the recently reported Mo-based catalysts. Only 261 mV overpotential and 1.53 V are required to drive oxygen evolution and overall water splitting in alkaline media. It is suggested that the interface-assisted phase transition is activated by electron and Co injections. The outstanding electrocatalytic performance originates from the porous structure, metallic conductivity and refined phase modulation synergistic with interfacial chemistry. Theoretical calculations show that the interfacial Co sites are activated for optimal hydrogen adsorption and water dissociation. Our work provides new ideas for the development of MOF-derived electrocatalysts for applications in energy-related fields.