Interface engineering of biomass-derived carbon-supported cobalt sulfide for enhanced oxygen evolution reaction

Biomass-derived carbon is an attractive catalyst support owing to its sustainability, porous structure, and good electrical conductivity. Herein, camphor leaf was selected as carbon precursor and CoS2@C catalyst was synthesized via a carbonization-hydrothermal-sulfuration process. The carbonization temperature and the Co/C mass ratio were optimized to improve the catalytic activity for OER. The otptimized CoS2@C catalyst exhibited an overpotential of 306 mV at current density of 10 mA cm-2 and smallest Tafel slope of 13.9 mV dec-1. The interfacial interaction between carbon substrate and CoS2 modulated the electronic structure of CoS2 and accelerated the electron transfer among the interface. In addition, the biomass-derived carbon supported CoS2 inhibited the aggregation and inactivation of active sites, increasing the stability of CoS2@C. This work provides a guidance of the synthesis of biomass-derived carbon supported metal compounds for electrochemical reactions.