One-Pot Synthesis of CuS/Co3S4@MWCNT Composite as a High-Efficiency Catalyst for the Hydrogen Evolution Reaction

Pursuing cost-effective non-precious metal electrocatalysts is a key challenge in the field of sustainable energy conversion. Transition metal dichalcogenides, known for their unique electronic structure, demonstrate superior electrocatalytic capabilities for the hydrogen evolution reaction (HER), yet their effectiveness is still lacking. In the present study, a CuS/Co3S4@MWCNT composite was fabricated via single-step hydrothermal synthesis for HER applications. This catalyst exploited the synergistic effects between CuS and Co3S4 to increase edge site functionalities and metallic conductivity, thereby resulting in high catalytical activity within the material. Furthermore, the incorporation of multi-walled carbon nanotubes (MWCNTs) into the composite effectively enhanced electron transfer kinetics throughout the HER process. Notably, thiourea serves a dual function in this synthesis, acting both as a reducing agent and as a sulfur source for the formation of metal sulfides. When evaluated in a 1 M KOH alkaline electrolyte, the synthesized nanocomposite exhibited a minimal overpotential of 300 mV to reach a current density of 10 mA/cm2, and a Tafel slope of merely 76.2 mV/dec, indicative of its good HER catalytic activity. These findings underscore the composite’s potential for application in hydrogen production technologies.