Nickel oxide nanoparticles dispersed on biomass-derived amorphous carbon/cobalt silicate support accelerate the oxygen evolution reaction

Abstract

The development of robust, low-cost and efficient oxygen evolution reaction (OER) electrocatalysts, especially non-noble-metal-based OER catalysts, is of great significance and imperative to address the energy crisis, but remain challenging. Herein, a biomass-derived three-dimensional (3D) porous carbon/cobalt silicate (C/Co₂SiO₄) architecture is developed as a support for loading nickel oxide (NiO_x) species to prepare an earth-abundant and non-noble-metal-based NiO_x/C/Co₂SiO₄ electrocatalyst. The NiO_x nanoparticles are dispersed on 3D C/Co₂SiO₄ support and the introduction of NiO_x species improves the OER active sites and shows the bimetal (Co, Ni) synergetic effect. The NiO_x/C/Co₂SiO₄ electrocatalyst exhibits the overpotential with 355 mV at 10 mA cm^-2, Tafel slope with 40 mV dec^-1 and large electrochemical active surface areas (ECSA), which are superior to C/Co₂SiO₄ support and NiO_x. The catalytic properties achieved herein are superior or comparable to most transition metal oxides/hydroxides. The findings reveal that the introduction of NiO_x nanoparticles can greatly boost the OER property of C/Co₂SiO₄ support. This work not only develops a non-noble-metal-based NiO_x/C/Co₂SiO₄ catalyst, but also verifies that the introduction of metal oxide species on biomass-derived 3D C/Co₂SiO₄ provides a new horizon to explore economical, high-efficient and robust OER catalysts.

Keywords: Cobalt silicate; Electrocatalyst; NiO(x) species; Oxygen evolution reaction; Three–dimensional support.