Formation of GO supported CoS2@MoS2 heterostructures with efficient electrocatalysis for water splitting

Abstract

Novel bifunctional catalyst, MoS2@CoS2 nanospheres grown on graphene oxide (CMS/GO), was successfully prepared. CMS/GO shows promising activity toward both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), with lower overpotentials of 90 mV for HER and 260 mV for OER at a current density of 10 mA/cm2. The corresponding Tafel slopes are 48 mV/dec and 52 mV/dec, respectively. The catalytic ability is significantly improved, which may derives from the synergistic effect between CoS2 and MoS2, the larger electrochemically active specific surface area coming from the larger BET surface area, the enhanced conductivity and active defects.