TiO2纳米粒子的光催化活性与光伏响应特性研究

TiO2纳米粒子由于其具有良好的化学稳定性、耐光腐蚀性、宽带隙能和大的比表面积等特点而被广泛地应用到光催化降解有机污染物^[1,2]和光催化储能等方面。由于研究手段和研究方法的限制，详细了解催化剂表面光生电荷行为、光谱谱带与催化活性的关系比较困难，而这些关系将为制备高催化活性的光催化剂提供理论基础，由于光催化活性的高低与催化剂的表面性质直接相关，表面光电压谱（SPS）是研究固体材料表面物性和界面间电荷转移过程的有利手段^[3]，其为控制光催化机理提供了新的手段。本文利用表面光电压谱方法对系纳米TiO2光催化剂进行了光伏响应测试，发现TiO2的晶型、粒径及表面吸附物对其光催化活性有很大影响。不同性质的表面吸附物可使催化剂表面呈现不同的导电特性，而使其光催化活性不同。利用能带理论和场效应原理对此进行了 合理的解释。

Researches on Photocatalytic Activities and Photovoltaic Properties of TiO2 Nanoparticles

We investigated the photovoltaic properties of series of TiO2 photocatalysts by means of SPS and found that the thresholds of TiO2 particles blue shift with their particle sizes decreasing and crystal phases changing from rutile TiO2 to anatase TiO2. Combining with the photodegradation activities of TiO2 on C7H16, it was concluded that the photocatalytic activities of TiO2 increase with their thresholds increasing,which can be explained using energy band theory. We also investigated the relationship beween the photovoltaic properties and photocatalytic activities of BTiO2 before and after photooxidation on C7H16, SO2 and C7H16+SO2, respectively and found adsorbates at the surface of TiO2 affect their photocatalytic activities and conduction types of surface layer.