Abstract: Hydrogen as a new energy plays a vital role in the future energy development.Hydrogen production from electrolyzed water includes two reactions of hydrogen evolution and oxygen evolution, which has the advantages of low price, no pollution, abundant reserves, and the oxygen evolution reaction is a rapid step in hydrogen production from electrolyzed water. A simple co⁃precipitation method was proposed to recombine carbon materials onto Co9S8 catalytic materials, and the oxygen evolution properties were characterized. Compared with Co9S8 without composite carbon material, a small amount of carbon material could significantly improve the oxygen production performance of Co9S8.The structure, morphology and electrochemical properties of the materials were tested by X⁃ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), polarization curves, chronoamperometry and AC impedance. The results show that the prepared Co9S8/C material has no impurity phase. When the current intensity is 10 mA/cm2, the overpotential is 350 mV, and the Tafel slope is 102 mV/dec, it has high electrocatalytic oxygen production performance.

Key words: Electrolyte, Co9S8, Oxygen evolution reaction, Coprecipitation method, Carbon material

摘要： 氢能作为新能源在未来的能源发展中发挥至关重要的作用。电解水制氢包括析氢和析氧两个半反应，具有低成本、无污染、储量丰富等优点，而析氧反应是电解水制氢中的决速步骤。介绍了一种简单的共沉淀方法，将碳材料复合到Co9S8催化材料上，并对其析氧性能进行了表征。对比没有碳材料复合的Co9S8，少量碳材料复合可以明显提高Co9S8的电解水析氧性能。通过X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、极化曲线、计时电流以及交流阻抗等技术对材料进行结构、形貌表征及电化学性能测试。结果表明，制备的Co9S8/C材料无杂相，在电流密度为10 mA/cm2时，过电势为350 mV，塔菲尔斜率为102 mV/dec，具有高的电催化产氧性能。

关键词: 电解水, 　Co₉S₈ , 　析氧反应, 　共沉淀方法, 　碳材料