Construction of interfacial engineering on CoP nanowire arrays with CoFe-LDH nanosheets for enhanced oxygen evolution reaction

Transition metal phosphides have recently emerged as promising alternatives for oxygen evolution reaction (OER). Herein, the OER performance of CoP nanowires was significantly enhanced by coupling with the cobaltiron layered double hydroxide (CoFe-LDH) nanosheets. The three-dimensional (3D) CoP@CoFe-LDH nanoarays heterostructure was fabricated by the sequential steps of hydrothermal process, phosphorization and electrodeposition. The as-prepared CoP@CoFe-LDH possesses well core?shell structure with a synergistic heterointerface between CoP and CoFe-LDH, in which the CoP core improves the conductivity and the CoFe-LDH shell affords abundant active sites. Furthermore, the 3D hierarchical architecture facilitates the electrolyte ions access and O2 gas liberation. Consequently, the optimized CoP@CoFe-LDH exhibits excellent OER performance with low overpotential (240 mV @ 40 mA cm-2), small Tafel slope (69.2 mV dec-1), superior intrinsic activity and high stability in 1 M KOH. This study demonstrates an efficient route to design the advanced OER catalysts by constructing the 3D core?shell heterostructure.