氢处理二氧化钛的光催化性能及电化学阻抗谱

通常可通过物理（浸渍法等）、化学方法（溶胶 -凝胶 ,电化学沉积法等）向光催化剂晶格中引入金属“小岛” ,以加速光生电子 -空穴的转移 ,提高改性后光催化剂的活性 1].同时 ,运用物理和光电化学等手段研究半导体光催化剂的表面性质和光电化学性质 ,可以为评价这些改性光催化剂的活性和研究反应机理提供依据 2,3].电化学阻抗谱 (EIS)方法是研究材料性质、化学 (特别是电化学 )过程和界面反应机理的有力工具 4].本工作运用 EIS手段研究了纳米 TiO_2在氢气气氛下热处理后 TiO_2的阻抗谱特征同其光催化活性之间的关系 .1实验部分　　…

Photocatalytic Activity and Electrochemical Impedance Spectroscopy of TiO_2 Thermally Treated by Hydrogen

TiO_2 treated in hydrogen atmosphere showed enhanced photocatalytic activity in degrading the sulfosalicylic acid (SSal).The results of the electrochemical impedance spectroscopy (EIS) investigation showed that the diameters of the capacitive arcs for the H-TiO_2 were much smaller than those of bare TiO_2 and thermally treated TiO_2 in air,indicating that the charge transfer of the H-TiO_2 occurs more rapidly,thus inviting a higher photocatalytic activity.When an external bias was applied on the H-TiO_2,the arc of the EIS Nyquist plot decreased obviously than without the bias,suggesting more efficient separation of the photo-generated carriers.