Encapsulation of bimetallic phosphides into graphitized carbon for pH-universal hydrogen evolution reaction

Exploring nonprecious electrocatalysts for water splitting with high efficiency and durability is critically important. Herein, bimetallic phosphides are encapsulated into graphitized carbon to construct a C@NiCoP composite nanoarray using bimetallic metal-organic framework (MOF) as a self-sacrificial template. The resulting C@NiCoP exhibits superior performance for pH-universal electrocatalytic hydrogen evolution reaction (HER), particularly representing a low overpotential of 46.3 mV at 10 mA cm(-2) and Tafel slope of 44.1 mV dec(-1) in alkaline media. The structural characterizations combined with theoretical calculation demonstrate that tailored electronic structure from bimetal atoms and the synergistic effect with graphitized carbon layer could jointly optimize the adsorption ability of hydrogen on active sites in HER process, and enhance the electrical conductivity as well. In addition, the carbon layer served as a protecting shell also prevents highly dispersed NiCoP components from agglomeration and/or loss in harsh media, finally improving the durability. This work thus provides a new insight into optimizing activity and stability of pH-universal electrocatalysts by the nanostructural design and electronic structure modulation. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

This study presents a high-performance electrocatalyst for pH-universal hydrogen evolution reaction by constructing a C@NiCoP composite nanoarray in alkaline media. The tailored electronic structure from bimetal atoms and the synergistic effect with graphitized carbon layer optimize the adsorption ability of hydrogen on active sites in HER process, enhancing both activity and stability.