锆掺杂二氧化钛基可见光催化剂的制备及其催化性能

采用溶胶-凝胶法制备了不同Zr掺杂量的Zr-TiO₂催化剂,并通过X射线衍射、扫描电子显微镜、傅里叶红外光谱对其进行表征,探究Zr元素的掺杂比例、催化剂制备的焙烧温度及反应物初始浓度等条件对催化剂在可见光下降解亚甲基蓝性能的影响。结果表明,制备的Zr-TiO₂催化剂粒径为纳米级,Zr-TiO₂催化剂对亚甲基蓝有明显光催化降解作用,且不同Zr与Ti掺杂比例对亚甲基蓝溶液降解效率影响显著,当Zr元素掺杂量为20%,焙烧温度为550 ℃时,制备的550℃-20%Zr-TiO₂催化剂对20 mg·L^-1的亚甲基蓝溶液降解效果最优,降解5 h时降解率为91.8%。并且550 ℃-20%Zr-TiO₂催化剂在可见光下催化降解亚甲基蓝符合一级动力学模型,R²>0.95,拟合直线有较好的拟合度,表明催化剂具有较强的降解能力。

Preparation and photocatalytic activities of zirconium-doped titanium dioxide-based visible light catalyst

In this experiment,TiO₂ catalysts with different zirconium doping contents were prepared by sol-gel method,and the prepared Zr-TiO₂ catalysts were analyzed by X-ray diffraction(XRD),scanning electron microscope(SEM)and Fourier infrared spectroscopy(FTIR).In addition,the effects of the doping ratio of zirconium,the calcination temperature of the catalyst preparation and the initial concentration of the reactants on the degradation of methylene blue under visible light were investigated. The results show that the particle size of the prepared Zr-TiO₂ catalyst is nanometer.Zr-TiO₂ catalysts have obvious photocatalytic degradation of methylene blue,and different Zr/Ti doping ratios have a significant effect on the degradation efficiency of methylene blue.When the doping amount of zirconium is 20% and the calcination temperature is 550 ℃,the prepared 550 ℃-20%Zr-TiO₂ catalyst has the best degradation activityfor 20 mg·L^-1 methylene blue solution,and the degradation efficiency is 91.8% after 5 h of reaction.And degradation of methylene blue under visible light over 550 ℃-20%Zr-TiO₂ accords with the first-order kinetic model,R²>0.95.The fitted straight line has a good fit,indicating that the catalyst has good degradation ability.