氮掺杂的二氧化钛可见光光催化降解亚甲基蓝

Photocatalytic degradation of methylene blue with nitrogen doped TiO_2 under visible light

采用气相法,以氨气为氮源,制备了氮掺杂的二氧化钛(N/TiO2)。紫外可见分光光度仪(DRS)测定结果表明,掺氮前后,TiO2的禁带宽度分别为3.09和2.98 eV,掺氮使TiO2的吸收光谱发生了红移。N/TiO2的可见光光催化降解亚甲基蓝的实验显示,反应的最佳条件为:亚甲基蓝的初始质量浓度为30 mg/L,pH为5.2。在最佳条件下,反应5 h后,亚甲基蓝的脱色率为96.6%。动力学研究证明,该反应符合拟一级反应,动力学常数为0.717 h-1。

Nitrogen doped TiO2 （N/TiO2） was fabricated by gas method with NH3 as nitrogen source. Diffused reflectance spectroscopy （DRS） showed that the band gap of TiO2 and N/TiO2 was 3.09 and 2.98 eV respectively, suggested that N doping made the adsorption spectrum a red shift. The optimum condition is as follows： the original concentration of methylene blue, 30 mg/L; pH, 5.2. The removal rate of methylene blue （MB） with N/TiO2 in photocatalytic process for 5 h was 96.6% under visible light. The reaction followed the preudo-first level kinetics model and the reaction rate constant was 0. 717 h^-1.