电解质溶液对聚吡咯电聚合中过氧化行为的影响

摘要

Polypyrrole(Ppy) was prepared by cyclic voltammetry on a platinum electrode in H2SO4/H2O and yClO4/CH3CN solutions, respectively. The effects of electrolyte solutions on overoxidation of polypyirole during its electrochemical polymerization were studied by in situ spectroelectrochemical measurements. Compared with the solution of H2SO4/H2O, the overoxidative peak potential of polypyrrole in LiClO4/CH3CN was positively shifted by 0. 42 V. The results show that theβ-C of the pentacycle is oxidized to oxygen-containing groups such as C-OH and C =O during the overoxidation of polypyrrole at high potentials. Polypyrrole partially degraded with the formation of CO2 in H2SO4/H2O solutions, which resulted in loss of conductivity, and did not obviously degrade during overoxidation in the solution UC1O4/CH3CN at the higher potentials.%分别以硫酸/水和高氯酸锂/乙腈为电解质溶液,采用循环伏安法在铂基底电极上电聚合制备了聚吡咯,研究了电解质溶液对聚吡咯电聚合过程中过氧化行为的影响.与硫酸/水溶液相比,在高氯酸锂/乙腈溶液中电聚合制备的聚吡咯发生过氧化的峰电位正移了0.42 V.采用原位傅里叶变换红外(in situ FTIR)光谱技术检测,结果表明,电聚合制备的聚吡咯在2种电解质溶液中均发生了过氧化反应,其β-C经氧化生成C-OH或C=O.在硫酸/水溶液中,部分聚吡咯发生电氧化降解生成CO2,致使其共轭结构被破坏,电导率迅速下降.而在高氯酸锂/乙腈溶液中,在更高的电位范围内,聚吡咯并没有氧化降解成CO2.