CoP nanowires coupled with CoMoP nanosheets as a highly efficient cooperative catalyst for hydrogen evolution reaction

The rational design and construction of efficient electrocatalysts play a leading role for water splitting, but very rarely Pt-like activity has been obtained by non-noble metal catalysts. It is obvious that the cooperative coupling of non-noble metal catalysts could be regarded as a preferred alternative to Pt-based materials in hydrogen evolution reaction (HER). Herein, a heterostructure electrocatalyst on Ni foam with CoP nanowires coupled with the defective CoMoP nanosheets (CoP/CoMoP) is first synthesized via hydrothermal method followed by low-temperature phosphidation. Results indicate that CoP/CoMoP shows extraordinarily efficient HER activity and robust stability, especially, high activity superior to that of commercial Pt/C in alkaline electrolyte, due to the cooperative effect of interfaces between CoP and CoMoP. Density functional theory (DFT) calculations certified that the interface between the CoP and CoMoP can improve the activity of HER, especially in alkaline condition, by facilitating the H2O-dissociation on the CoMoP and H-adsorption on the CoP. Moreover, the CoMoP with P defects can enhance the activity of HER by preventing the active sites of CoMoP and CoP from the blocking of OH*. It is expected that such heterostructure CoP/CoMoP could provide a powerful interface-engineering strategy to design and construct efficient cooperative electrocatalysts for HER.