In-situ construction of lattice-matching NiP2/NiSe2 heterointerfaces with electron redistribution for boosting overall water splitting

High-efficiency electrocatalysts for water splitting can be achieved by constructing heterostructure engineering purposely. The same pyrite structure of NiSe 2 /NiP 2 with admirable electrical conductivity of NiSe 2 and outstanding stability of NiP 2 is designed to boost electrocatalytic performance towards overall water splitting. Density functional theory (DFT) calculations identify that constructing NiP 2 /NiSe 2 heterointerfaces with good lattice matching and the redistribution of electron between the heterointerfacecan optimize adsorption/desorption energy of H* effectively. Therefore, NiP 2 /NiSe 2 heterostructure on carbon fiber cloth with one-step phosphoselenization is developed as electrocatalysts. As expected, NiP 2 /NiSe 2 exhibits excellent catalytic activity with only 160 mV overpotential to realize a current density of 100 mA cm −2 and exceptional stability over 90 h at the current density of 10 mA cm −2 for HER in alkaline solution. This heterostructure strategy might be a new break-through for modulating the single-phase transition metal and designing highly active and durable catalysts towards water splitting.