采用水热法制备Bi/MCNOs电极催化剂，通过XRD、SEM对Bi/MCNOs催化剂进行表征，考察了Bi/MCNOs电极电化学还原CO₂制甲酸的性能。结果表明，在水热过程中，MCNOs成功负载到Bi上，Bi/MCNOs具有更小的球状结构。Bi/MCNOs电极电化学活性表面积为Bi电极的3.4倍。Bi/MCNOs电极的电流密度是Bi电极的4倍，且具有更正的起峰电位。通过对KHCO₃电解液浓度、还原电位对电化学还原CO₂制甲酸的分析可知，KHCO₃电解液浓度为0.5 mol/L、电势为-1.6 V vs.Ag/AgCl时，电化学还原CO₂效果最好，具有较高的电流效率。由此可见，Bi/MCNOs电极具有更高的活性，可有效提高电化学还原CO₂的催化效果。

Bi/MNCOs electrode catalyst is prepared through hydrothermal method,and characterized by means of XRD and SEM.Its performance in electrochemical reduction of CO₂ to formic acid is studied.XRD reveals that MCNOs have successfully been loaded on the surface of Bi during hydrothermal process.SEM indicates that Bi/MCNOs have a smaller spherical structure,which can enhance specific surface area.Cyclic voltammetry curves at different scan rates show that the electrochemical active surface area and current density of Bi/MNCOs are respectively 3.4 times and 4 times that of commercial Bi electrode,with a more positive onset potential than the latter.It is found through analysis that the electrochemical reduction of CO₂ over Bi/MNCOs electrode catalyst can reach the best with a higher current effect when the concentration of KHCO₃ electrolyte is 0.5 mol·L^-1,the potential is at -1.6 V vs.Ag/AgCl.It is presented that Bi/MNCOs electrode can effectively improve the catalytic effect of electrochemical reduction of CO₂.

龚浩(1998-),男,硕士研究生,研究方向为电化学还原二氧化碳,2656191707@qq.com;高利珍(1965-),男,博士,教授,研究方向为催化化学,通讯联系人,gaolizhen@tyut.edu.cn。