方菁染料敏化二氧化钛超微粒的光化学行为  

Investigation of Photochemical Behavior of a Squaraine Dye Photosensitizing Titanium Dioxide Ultrafine Particles

作　　者：王传义[1] 刘春艳[1] 沈涛[1] 

机构地区：[1]中国科学院感光化学研究所,北京100101

出　　处：《化学学报》1998年第5期427-432,共6页Acta Chimica Sinica

基　　金：国家自然科学基金(29573141);中国科学院感光化学研究所光化学开放实验室和美国柯达公司的资助

摘　　要：通过吸收光谱、荧光猝灭、单光子计数等手段研究了2-(4-乙胺-2-羟基苯基)-4-(4-乙胺-苯基)-方菁染料(SQ)在TiO_2超微粒体系中的光化学行为.结果表明,SQ强烈吸附在TiO_2胶粒表面,表观吸附常数为2.275×10~3mol^(-1)·dm^3.SQ的荧光能被TiO_2有效地猝灭,猝灭的效率达97%.根据物质的氧化还原电位、光谱特性及荧光寿命的变化提出光诱导电子界面转移的荧光猝灭机理,电子转移的速率常数为1.97×10~8_s^(-1).Photochemical behavior of 2 - (4 - ethylamino - 2 - hydroxyphenyl) - 4 - (4 -ethylaminophenyl) - squaraine (SQ) in TiO2 system was probed by UV - vis, fluorescence quenching, and nanosecond time - correlated single - photon counting. There was strong interaction between SQ and TiO2 colloidal particles with an apparent association constant of 2. 275×103mol-1·dm3 obtained by the fluorescence quenching data. The fluorescence emission of SQ dye could be quenched by TiO2 colloid with an efficiency of 97 % . The mechanism of photoinduced interface electron transfer for the fluorescence quenching was proposed upon the spectral characters, potential discrepancy and the variation of the fluorescence lifetime. The rate constantfor the electron injection process was 1. 97 × 108 s-1 determined from the measurements of fluorescence lifetimes.

关 键 词：方菁染料 二氧化钛超微料 光催化剂 敏化 

分 类 号：O643.36[理学—物理化学]