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 NiSe2/NiP2 with admirable electrical conductivity of NiSe2 and outstanding stability of NiP2 is designed to boost electrocatalytic performance towards overall water splitting. Density functional theory (DFT) calculations identify that constructing NiP2/NiSe2 heterointerfaces with good lattice matching and the redistribution of electron between the heterointerfacecan optimize adsorption/desorption energy of H* effectively. Therefore, NiP2/NiSe2 heterostructure on carbon fiber cloth with one-step phosphoselenization is developed as electrocatalysts. As expected, NiP2/NiSe2 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.