Hierarchical NiOx nanotube arrays/CoP nanosheets heterostructure enables robust alkaline hydrogen evolution reaction

Rational design of low-cost and high-efficiency electrocatalysts for hydrogen evolution reaction (HER) is critical for scalable and sustainable hydrogen production from economical water-alkali splitting. Herein, density functional theory (DFT) calculations reveal that coupling NiOx and CoP could effectively boost overall HER kinetics through lowing the H2O dissociation barrier, accelerating the OH* transfer process, and providing the rapid H* migration kinetics as well as the appropriate H* energetics. Based on these findings, we successfully prepared a three-dimensional (3D) self-supported electrode of ultrathin CoP nanosheets directly grown on the surfaceoxidized Ni nanotube arrays via a simple and scalable electrochemical synthesis method. As expected, such a heterostructure electrode exhibits superior alkaline HER performance with low overpotentials of 51 and 164 mV to drive the current densities of 10 and 500 mA cm-2, respectively, outperforming most of the efficient alkaline HER electrocatalysts.

Automated summary

Rational design of low-cost and high-efficiency electrocatalysts for hydrogen evolution reaction is critical for scalable and sustainable hydrogen production. Coupling NiOx and CoP can effectively boost the overall HER kinetics by lowering the H2O dissociation barrier and accelerating the OH* transfer process. The prepared CoP nanosheets on Ni nanotube arrays exhibit superior alkaline HER performance, outperforming most efficient alkaline HER electrocatalysts.