Morphology-controlled synthesis of Cu2S for efficient oxygen evolution reaction

The overpotential of oxygen evolution reaction plays a key role in electrolysis water which is essential for the efficient utilization of electrolysis water. In this paper, CF/Cu2S composite structure was synthesized by one-step hydrothermal. Scanning electron microscope show that the proportion and morphology of needle-like and nano-flake Cu2S by adjusting the water alcohol ratio of hydrothermal reaction. Electrochemical characterization show that the oxygen evolution overpotential of CF/Cu2S with different morphology ranged from 239 mV to 384 mV. The CF/Cu2S with the water alcohol ratio of 9/1 has the lowerest oxygen evolution overpotential at 239 mV and Tafel slope at 199 mv-dec(-1) which is origined from the largerest contact area between electrons and electrolyte, thus improved charge transfer ability and effectively decrease the overpotential of oxygen evolution reaction. These results suggested that the active site could be efficiently increase and the overpotential of CF/Cu2S could be effectively decrease by adjusting their morphology and realize the efficient oxygen evolution reaction of electrolysis water.