【摘要】 用溶胶-凝胶法在石英管上制备了纳米TiO2膜,并采用光催化氧化法建立了一种测定地表水化学需氧量(COD)的新方法.以Ce(IV)作为纳米TiO2光生电子的接受体,从而减少了纳米TiO2光生电子和光生空穴的复合,提高纳米TiO2的光催化氧化能力.以测定Ce(IV)的紫外吸收为手段探讨了光催化氧化测定COD的机理,考察了测定COD的最佳反应条件.实验结果表明,该方法条件温和,不会造成二次污染,能够实现地表水等低COD值水样的快速准确测定.在该实验所选择的条件下,可准确地测定1.0～12mg?L-1之间的COD值,检测限为0.4mg?L-1.更多还原

【Abstract】 A photocatalytic oxidation method for the detection of the chemical oxygen demand (COD) of the ground water using sol-gel-based nano-TiO2 film, which was coated onto the quartz tube, was proposed. In this method, the photo-exited conduction band electrons released from illuminated nano-TiO2 film could be easily accepted by Ce(IV) to enhance the activity of photocatalytic degradation of organic compounds. Therefore, the COD of a given sample can be assessed by determination of the change of the concentration of Ce(IV). Under the optimum operation conditions, the determination range of COD was 1.0～12 mg?L-1 and the limit of detection was 0.4 mg?L-1. This method was also applied to the determination of the COD of ground water samples. The results were in good agreement with those from the conventional (i.e., perman- ganate) COD methods.更多还原