聚吡咯/TiO_2复合材料的制备及其光催化性能研究

Preparation and photocatalytic performance of PPy/TiO_2 nano-composite material

为了降低二氧化钛的禁带宽度,拓宽其在可见光区的光响应范围。以光敏剂吡咯为原料,采用原位聚合法制备了不同聚吡咯含量的聚吡咯/二氧化钛(PPy/TiO2)复合光催化剂材料。利用X射线衍射(XRD)、红外光谱仪(FT-IR)、扫描电子显微镜(SEM)等对复合材料做了表征。研究了纯TiO2以及不同吡咯添加量制备的PPy/TiO2复合材料在可见光照下对罗丹明B的降解率。紫外-可见漫反射光谱表明,吡咯添加量为0.5 m L时TiO2的禁带宽度由原来的3.11 e V降为2.90 e V;由光催化降解罗丹明B的实验可知:在光强为100 m W/cm2、吡咯添加量为0.5 m L、降解时间为3 h时,罗丹明B的降解率达到了最大值87%,而纯的TiO2的降解量仅为57%;综合实验分析结果可知,由适量吡咯掺杂的TiO2的可吸收的波长范围拓宽到可见光区,复合材料在可见光区的光催化能力得到了提升。

In situ oxidative polymerization was adopted to prepare TiO2/polypyrrole composite photocatalyst materials using photosensitizer pyrrole as raw material to decreaseTiO2＇s band-gaps and extend its response range to the visible light.The composite materials were characterized by X ray diffractometry, FT-IR, and scanning electron microscope etc..The degradation rates of rhodamine B under visible light of pure TiO2 and PPy/TiO2 nanoeomposites obtained doped with different amounts of pyrrole have been investigated.UV-visible diffused reflection spectra showed When 0.5 mL of Py was doped the band-gaps of TiO2 was down to 2.90 eV from 3.11 eV.The experiments of photocatalysis degradation of rhodamine B indicated that ,when the doping of lay was 0.5 mL,radiating under visible light of 100 mW/cm2 for 3 h ,the degradation of rhodamine B reached the max value of 87% ;While the pure TiO2 photocatalytie efficiency was only 57%.Comprehensive experimental resuits indicated that an appropriate doping content ofpy could extend TiO2＇s response range to the visible light and the photocatalytic capability of composite materials under visible light could be effectively improved.