电场协助对Ag/TiO_2光催化降解效率的影响

Combined Effect of Electro-assist and Silver Modification for TiO_2 Photocatalysis

在三维立体光电催化反应器中,以Ag/TiO2为光催化剂,网状钛板为电极,对苯酚和甲基橙进行光/电/贵金属协同催化降解,研究电场协助对Ag/TiO2光催化降解效率的影响。考察了阳极偏压大小、电解质种类、pH值对Ag/TiO2光电催化反应的影响;采用紫外-可见全反射光谱(ERS)、紫外-可见漫反射光谱(DRS)和傅利叶变换红外光谱(FTIR),对Ag/TiO2光催化剂的能阈结构、光谱特征、表面结构等进行表征。结果表明,外加适宜的阳极偏压(苯酚10V和20V,甲基橙10V和大于25V)可显著提高Ag/TiO2光催化降解效率;电解质NaCl的加入可提高Ag/TiO2光电催化反应速率;适宜的光电催化反应酸度值为pH7.0(未加电场时为pH5.5)。

The effect of electro-assist combined with silver modification for TiO2 photocatalysis was investigated. The effects of anode bias potential, electrolyte and pH on the photocatalytic degradation of phenol and methyl orange （MO） over Ag/TiO2 were evaluated. Entirely reflectance spectrum （ ERS）, Diffuse reflectance spectroscopy （DRS） and Fourier Transformation Infarred （FTIR）spectrum were used to determine the optical surface characteristics and of Ag/TiO2. The results showed that the suitable potential bias （ 10 V and 20 V for phenol, 10 V and above 25 V for MO）were beneficial to Ag/TiO：photocatalysis. Electrolyte NaCl can enhance the reaction rate, pH 7.0 was suitable for photoelectrocatalytic degradation （5.5 for the reaction without electro-assist）.