TiO_2光催化剂在COD测定中的应用研究

APPLICATION OF TiO_2 PHOTOCATALYST APPLIED IN COD DETECTION

采用溶胶-凝胶法制备纳米TiO2薄膜电极,提出了一种简便、快速测量化学需氧量(COD)的方法。分别以葡萄糖、邻苯二甲酸氢钾(KHP)为COD检测的标准物,考察了TiO2薄膜的光催化行为,并与传统方法进行比较。实验结果表明,葡萄糖对紫外光几乎没有吸收,在葡萄糖的电解质溶液中,COD与光电流有很好的一元二次关系;KHP对紫外光有吸收,在KHP的电解质溶液中,当COD浓度大于50mg/L时,随着COD浓度的增加,光电流降低。引入了单位光强度引起的电流响应(E)这一变量,该传感器的单位光强度引起的电流响应E与COD值在15.0～300mg/L范围内有很好的一元二次关系,相关系数为0.9999,并且不同样品在薄膜电极上的E呈现很好的线性关系。该传感器对水样的测量结果与传统方法测量结果相吻合。

The nanosized TiO2 film electrode were prepared by sol - gel method, and applied for chemical oxygen demand （COD） determination. The photocatalytic behavior of the TiO2 film electrode was studied when glucose and potassium acid phthalate were used as COD detection standards. The method was compared with the dichromate COD analysis method. The results showed that in the glucose electrolyte solution, the COD value was unitary quadratic equation to the photocurrent due to no absorbing ultraviolet. In the potassium hydrogen phthalate （KHP） electrolyte solution, the photocurrent reduced with the COD value increasing, when the COD value was more than 50 mg/L. The photocurrent brought by unit luminous intensity （E） was introduced. E was unitary quadratic equation to the COD value in the range of 15.0 - 300 mg/L with a correlation coefficient of 0. 999 9. The E detection results of deferent samples were linearity. The detection result by this method was in accord with that of traditional method.