Template-directed bifunctional dodecahedral CoP/CN@MoS₂ electrocatalyst for high efficient water splitting

Designing high efficient and noble metal-free bifunctional electrocatalysts for both hydrogen and oxygen generation is still critical and challenged. In this study, hierarchical dodecahedral-structured CoP/CN@MoS₂ is prepared through a two-step calcination treatment and a solvothermal approach. The metal-organic framework of ZIF-67 is chosen to serve as the template and for providing Co sources, in which ZIF-67 is first transformed to Co nanoparticles embedded in nitrogen-doped carbon polyhedrons and then transformed to CoP/CN. MoS₂ nanosheets are further grown on the surface of dodecahedral-structured CoP/CN with a solvothermal method. Benefiting from the synergistic coupling effect of CoP and MoS₂ and the nitrogen-doped carbon matrix, advanced hydrogen evolution reaction (HER) both in acid and alkaline solution as well as splendid oxygen evolution reaction (OER) performance in alkaline aqueous were achieved. Moreover, the coupling effect of CoP/CN and MoS₂ is disclosed theoretically by density functional theory calculations to validate the increased HER activity. The as-prepared hybrid CoP/CN@MoS₂ not only exhibits decent HER activity in acidic (η₁₀ = 144 mV) and alkaline solutions (η₁₀ = 149 mV), but also exhibits splendid OER activity (η₁₀ = 289 mV) in 1.0 M KOH. This work represents a solid step toward boosting the electrocatalytic kinetics of nonprecious catalysts.