Preparation of hard magnetic Co2C nanospheres as electrocatalysts for hydrogen evolution reaction

Abstract

Cobalt carbide as a new type of transition metal carbides (TMACs) has received extensive attention in the field of magnetism and electrocatalysis. As one of the cobalt carbide materials, Co2C shows good hard magnetism. In this paper, we have designed a simple and efficient method to successfully prepare single-phase Co2C nanospheres. Co2C is synthesized by using Co3O4 as precursor and small molecule amino ethylenediamine as carbon source. The material exhibits excellent hard magnetic properties, with saturation magnetization up (Ms) to 32.19 emu/g and coercivity up to 1111 Oe at room temperature. Co2C also demonstrats excellent hydrogen evolution reaction performance in 1 M KOH solution. Using nickel foam as the working electrode, the overpotential of only 92 mV can reach the current density of 10 mA cm−2, and the Tafel slope is 104 mV dec−1. This provides a new idea for the further development of synthetic cobalt carbide and its composite materials.