【摘要】 采用sol-gel法制备了系列纳米TiO2光催化剂,运用X射线衍射、BET比表面测定、紫外漫反射吸收光谱和表面光电压谱等手段对催化剂进行表征,并以乙烯作为光催化反应的指标反应分子,研究了TiO2纳米晶的性质对于光催化活性的影响.随着焙烧温度的升高,TiO2的晶粒逐渐增大,比表面积下降,晶相由锐钛矿向金红石转变,其吸收带边与光伏响应阈值向长波方向移动,氧化-还原能力降低,降解乙烯的转化率迅速下降.更多还原

【Abstract】 TiO2 photocatalysts prepared by sol gel method were characterized by X ray diffraction (XRD),UV diffuse reflectance spectroscopy (DRS),N2 adsorption BET method,surface photovoltage spectroscopy (SPS).A test compound ethylene in the gas phase was employed in the heterogeneous photocatalytic oxidation to investigate the effects of properties of TiO2 nanoparticles on photocatalytic performance.The results showed that crystal size of TiO2 increased slowly and its surface area downgraded with the increasing of calcination temperature;the crystal phase of TiO2 changed from anatase to rutile,the threshold of SPS decreased and the band edge red shifted to yield smaller redox potential,leading to the significantly decreased of photocatalytic activity.更多还原