【摘要】 对甲基紫精（Ⅰ）、聚烃撑紫精（Ⅱ）和烃撑二甲基紫精（Ⅲ）三类紫精型电子中继物进行了比较研究。用循环伏安法考察了它们的氧化还原特性及伏安图形在连续多次循环中的重现性。用原位紫外一可见光谱观察了恒电位电解过程中不同紫精还原态的生成及其变化。还比较了以紫精为电极电子传输物的光电化学池的光电流曲线。讨论了反应条件与体系稳定性的关系,并指出光敏剂与紫精电位的配合以下列顺序为宜: E_H2O/H2>E_v²⁺/v⁺>E_SP⁺/SP^*>E_v⁺/v·更多还原

【Abstract】 Three types of viologens.comparatively.Their redox characteristics and revesibility in redox were investigated by the multicyclic potential sweeping technique,and the formation as well as the change of the reduced viologens produced during controlled potential electrolysis was followed with absorption spectra in situ.The behavior of photoelectrochemical cells containing different viologens was also examined.(Ⅰ) was found to possess a more negative redox potential and a greater ability for electron transfer,but was less stable to oxygen.The absorption spectra of the reduced state V+ of (Ⅱ) and (Ⅲ) were shown to be violet shifted compared with that of MV+.A serious detriment in reversibility of the viologens was confirmed to be due to the formation of V and their aggregation.In order to improve the stability of the catalyst system for H2-photogeneration from water,it was proposed that the viologen and photosensitizer used as catalyst components should possess the potential order E(H2O/H2)>E(V2+/V+)>E(PS+/PS)>E(V+V/V0) and the reaction condition should be adjusted in such a way so that the evolution of hydrogen could match the formation of V+ in velocity.更多还原