Structure and Photocatalytic Activity of Polythiophene/TiO2 Composite Particles Prepared by Photoinduced Polymerization

Abstract

Polythiophene/titanium dioxide (PTh/TiO 2 ) composite particles were synthesized via the photoinduced polymerization of thiophene in a TiO 2 -chloroform suspension. The resultant composite particles were characterized by BET analysis, scanning electron microscopy, laser particle size analysis, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The XPS spectra indicated that a strong interaction exists between the S sites of the polymer backbone and the TiO 2 particles. The UV-Vis DRS spectra showed that the resultant composite particles are responsive to visible light. The photocatalytic activities of the PTh/TiO 2 composite particles were examined through the degradation processes of a rhodamine B (RhB) solution under UV irradiation and visible light irradiation. The degradation ratios of the RhB solution were found to be 76% and 98% after UV irradiation (180 min) and visible light irradiation (10 h), respectively. The photocatalysis reactive mechanisms under UV irradiation and visible light irradiation were investigated using disodium ethylenediamine tetraacetate (EDTA-2Na, hole scavenger) and furfuryl alcohol (radical scavenger). The oxidant from the holes and the radicals are competitive. Under UV irradiation, photogenerated holes are the main active species while under visible light irradiation the radicals are the main oxidant for the degradation of RhB. ：通过光诱导噻吩在 TiO 2 的氯仿悬浮液中聚合反应, 制备了聚噻吩/二氧化钛 (PTh/TiO 2 ) 复合粒子, 并采用比表面积分析仪、扫描电子显微镜、粒径分析仪、X 射线光电子能谱、紫外-可见漫反射光谱和红外光谱对复合粒子进行了表征. 结果表明, PTh/TiO 2 复合粒子上的聚噻吩骨架中 S 原子与 TiO 2 粒子间存在强相互作用, 该复合粒子对可见光具有响应. 以罗丹明 B 为模型污染物, 研究了该复合粒子在紫外光和可见光照射下的光催化活性. 分别以乙二胺四乙酸二钠和呋喃甲醇为空穴捕捉剂和自由基捕捉剂研究了 PTh/TiO 2 复合粒子在紫外光和可见光照射下的光催化反应机理. 结果表明, 空穴和自由基是主要的光催化反应中的氧化性物质. 在紫外光照射下, 空穴起主要作用; 在可见光照射下, 自由基起主要作用. Polythiophene/titanium dioxide (PTh/TiO2) composite particles were synthesized via the photoinduced polymerization of thiophene. The photocatalytic reactivity of the composites under UV irradiation is better than that of TiO 2 . These composites can degrade rhodamine B under visible light irradiation.