分子筛修饰电极中内电子传输机理的研究

Studies on Intrazeolite Electron Transfer Mechanism of Zeolite modified Electrodes

用电化学方法聚合分子筛孔道内的苯胺，以聚苯胺分子筛修饰电极为模型研究分子筛修饰电极的内电子传输机理．ＮａＹ分子筛的离子交换点位被苯胺修饰后，通过电聚合制得聚苯胺分子筛修饰电极（Ｐａｎ＋Ｙ－ＺＭＥ），该电极通过聚苯胺链自身的电子跳跃来实现电子传输，且只有通过阴极富集后对溶液中Ｃｄ２＋才有响应。

This paper is concerned with the mechanism of intrazeolite electron transfer in zeolite modified electrodes(ZMEs) where the zeolite have been modified with polyaniline. First, data were obtained from ZMEs prepared with zeolite Y loading aniline and the electropolymerizing of anilines was performed by cyclic voltammery. Polyaniline might not leak out from zeolite due to the bulk size of polyaniline being bigger than the channel of zeolite Y. At the absence of electron transfer mediators, the Pan +Y ZME showed the expected presence of electron hopping of adjacent polyaniline cations. Second, the data were obtained for the determining Cd 2+ and ascorbic acid using Pan +Y ZME. The Cd 2+ might not be preconcentrated at open circuit and could be done at constant potential. At the absence of ion exchange between zeolite and surrounding electrolyte the electron transfer was performed via the electron hopping, i.e . by an intrazeolite mechanism; rather than by an extrazeolite mechanism. In addition, the ascorbic acid molecule and its anion could not cross zeolite film to base electrode therefore, its current was conducted also by the electron hopping between the chains of polyaniline. Experimental results indicate that the electron transfer of Pan +Y ZME was dominated by intrazeolite processes.