TiO_2薄膜光电极能带结构和催化活性的初探  

Preliminary Study on Band Structure of TiO_2 Thin Photoelectrode and Catalytic Activity

作　　者：孔海霞[1] 孙彦平[1] 武爱莲[1] 

机构地区：[1]太原理工大学洁净化工研究所,山西太原030024

出　　处：《感光科学与光化学》2004年第5期327-332,共6页Photographic Science and Photochemistry

基　　金：国家自然科学基金(29776032);山西省自然科学基金(971013).

摘　　要：以阳极氧化法制得的TiO2薄膜光电极为工作电极,铂环为对电极,饱和甘汞电极为参比电极,组成光电催化降解苯酚体系.运用电化学阻抗图谱(EIS),测得光电催化过程中TiO2薄膜光电极的空间电荷层电容,计算出半导体能带结构参数———空间电荷层宽度W.结果证明:当空间电荷层宽度W随阳极偏压增加而增大时,TiO2薄膜电极光催化活性提高;当其等于薄膜厚度时,光催化活性最好,此时出现最佳偏压值;继续增加偏压,活性反而有所下降.A three-electrode system composed of TiO_2 photoelectrode as the working electrode,Pt ring as the counter electrode and saturated calomel electrode (SCE) as the reference electrode was used for the photoelectrocatalytic degradation of phenol.The TiO_2 thin film photoelectrode was made by anodizing.During the photoelectrocatalytic process,Electrochemical Impedance Spectroscopy (EIS) was applied to measure the capacitance of space charge layer in the TiO_2 semiconductor photoelectrode,and to calculate the band structure parameter-the width W of space charge layer.The results show that photocatalytic activity of TiO_2 electrode is improved when the width broadens with the bias increasing; the activity reaches best when the width is nearly equivalent to the thickness of TiO_2 thin film,then the optimal value of the bias appears; the activity somewhat decreases when the bias is beyond the optimal value.

关 键 词：TiQ薄膜 半导体光电极 电化学阻抗图谱 苯酚降解 

分 类 号：O643.3[理学—物理化学]