Controlled synthesis of NixP-Co2P hybrid materials as robust overall water splitting electrocatalyst

Environmentally friendly overall water splitting electrocatalysts can be exploited through construction of efficient heterogeneous interfaces. Flexible preparation of lattice-matching Ni2P–Co2P heterointerfaces is exploited to promote electrochemical activity for overall water splitting because of the outstanding electrical conductivity of Co2P and admirable durability of Ni2P. Density functional theory calculations demonstrate that construction of lattice-matching Ni2P–Co2P heterogeneous interfaces and the regulation of density of states between the heterogeneous interfaces can effectively optimize the water adsorption energy. Hence, a series of NixP-Co2P hybrid materials were in site grown on nickel foam through hydrothermal synthesis and phosphorization approach. What is noteworthy is that the Ni2P–Co2P-0.5//Ni2P–Co2P-1 electrode couple presents superior electrochemical performance with only 1.60 V cell voltage to obtain a current density of 10 mA cm−2 under alkaline condition. In addition, the Ni2P–Co2P-0.5//Ni2P–Co2P-1 electrode couple display superior durability over 15 h at large current densities of 30 mA cm−2 during water electrolysis process. The construction of heterostructures is conducive to the regulation of state density and the maximization of synergistic catalytic effect. The work provides a novel idea for the exploitation of highly efficient and robust water electrolysis catalysts and this work might be a new breakthrough for the construction of lattice-matching hybrid structures.