铋/纳米洋葱碳电极的制备及其电化学还原CO_(2)性能研究

Preparation of Bi/MCNOs electrode and its performance in electrochemical reduction of CO_(2)

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CO_(2)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KHCO_(3)电解液浓度、还原电位对电化学还原CO_(2)制甲酸的分析可知,KHCO_(3)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CO_(2)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CO_(2)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 CO_(2) 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 CO_(2) over Bi/MNCOs electrode catalyst can reach the best with a higher current effect when the concentration of KHCO_(3) 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 CO_(2).