Enhanced Electron Transfer and Ion Transport by Binary and Multidimensional CuCo₂ S₄ /Fe₂ O₃ on Carbon Cloth for Water Oxidation

The behavior of electron transfer and ion transport plays a significant role in the electrocatalytic activity. However, the improvement of CuCo₂ S₄ electrocatalytic activity has been a difficult problem owing to lack of effective electron transfer and ion transport. Herein, the unique structure connected CuCo₂ S₄ nanosheets and carbon cloth (CC) with Fe₂ O₃ nanoparticles to form CuCo₂ S₄ /Fe₂ O₃ /CC. Compared with CuCo₂ S₄ /CC, the resistances of electron transfer and ion transport were decreased by 65 and 84 %, respectively. The electrochemical surface area of CuCo₂ S₄ /Fe₂ O₃ /CC was 2.76 times larger than that of CuCo₂ S₄ /CC due to the high double-layer capacitance. For the oxygen evolution reaction, CuCo₂ S₄ /Fe₂ O₃ /CC could achieve an overpotential of 273 mV and a Tafel slope of 67 mV dec^-1 in alkaline solution.