Eosin敏化不同晶体结构TiO_2的产氢性能研究

Research on Photocatalytic Hydrogen Production of Eosin Sensitized Different Structure of TiO_2

采用超声法制备了TiO2的纳米粒子,经处理后得到不同晶体结构的TiO2.使用硅烷偶联剂修饰TiO2表面,加入脱水剂和Eosin,在蒸馏条件下,TiO2表面的氨基与Eosin分子中的羟基脱水后使得Eosin分子稳定吸附在TiO2表面.Eosin的敏化使TiO2对光的响应扩展到可见光区,并产生可见光解水产氢活性.紫外-可见漫反射光谱结果说明,锐钛矿型催化剂和混晶结构催化剂的能隙分别为2.0 eV和2.1 eV.在三乙醇胺水溶液中进行可见光下的光解水产氢实验,结果表明混晶结构的催化剂无产氢活性,锐钛矿型催化剂的光解水产氢活性最高,420 nm处的量子效率为2.32%,480 nm处的量子效率为2.86%,产氢速率在60 h内基本保持稳定.

The ultrasonic method is used to synthesize titanium oxide nanocrystals. Productions with different crystal-structure are generated by calcination at different high temperature. The silane-coupling reagent is used to construct a stable absorbance of eosin on TiO2. The results of Uv-Vis diffraction spectrum indicate that the bandgaps for anatase-production and mixed-structure-productions are 2. 1eV and 2.0 eV respectively. But the eosin sensitized TiO2 with mixedstructure has no activity in triethanolamine water solution because of small surface areas, while the anatase-structure photocatalyst has a comparatively high activity. It has an apparent quantum efficiency of 2.32% at 420 nm and 2. 86 % at 480 nm.