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

Abstract

Environmentally friendly overall water splitting electrocatalysts can be exploited through construction of efficient heterogeneous interfaces. Flexible preparation of lattice-matching Ni 2 P–Co 2 P heterointerfaces is exploited to promote electrochemical activity for overall water splitting because of the outstanding electrical conductivity of Co 2 P and admirable durability of Ni 2 P. Density functional theory calculations demonstrate that construction of lattice-matching Ni 2 P–Co 2 P heterogeneous interfaces and the regulation of density of states between the heterogeneous interfaces can effectively optimize the water adsorption energy. Hence, a series of Ni x P-Co 2 P hybrid materials were in site grown on nickel foam through hydrothermal synthesis and phosphorization approach. What is noteworthy is that the Ni 2 P–Co 2 P-0.5//Ni 2 P–Co 2 P-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 Ni 2 P–Co 2 P-0.5//Ni 2 P–Co 2 P-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. • A series of Ni x P-Co 2 P materials were prepared through hydrothermal and phosphorization approach. • The electrode presents superior electrochemical performance with 1.60 V to drive 10 mA cm −2 . • These experimental results are consistent with the DFT calculations predictions.