可见光下氮掺杂罗丹明B分子印迹TiO_2的选择性光催化性能

采用溶胶-凝胶法和分子印迹技术,以尿素为氮源、罗丹明B为模板分子制备了氮掺杂罗丹明B分子印迹TiO_2粉末(N-TiO_2-RhB),并对样品进行了XRD、UV-Vis DRS和BET表征。表征结果显示:氮掺杂和分子印迹一定程度改善了样品的孔隙结构和孔径分布,N-TiO_2-RhB的比表面积和孔体积分别为TiO_2的1.9倍和1.5倍;氮掺杂使TiO_2的光吸收带边发生红移,而分子印迹不能改变催化剂的光吸收带边。N-TiO_2-RhB具有最佳的可见光活性和选择性,对罗丹明B的降解率高达92.7%。对罗丹明B、罗丹明6G、甲基紫和甲基绿的降解过程均符合一级反应动力学方程。

Selective photocatalytic activity of Rhodamine B molecular imprinted N-doped TiO2 under visible-light

Using urea as nitrogen source and Rhodamine B as template molecule,Rhodamine B molecular imprinting N-doped titanium dioxide （N-TiO₂-RhB） powder was prepared by sol-gel method and molecular imprinting technique,and characterized by XRD,UV-Vis DRS and BET. The results showed that：The pore structure and pore size distribution of the sample were improved by doping and molecular imprinting;The specific area and pore volume of N-TiO₂-RhB were 1.9 and 1.5 times as large as TiO₂;N-doping led to red shift of TiO₂ absorption edge,while molecular imprinting can’t change the optical absorption edge of the catalyst. N-TiO₂-RhB had the best photocatalytic activity and selectivity under visible-light,the degradation rate of Rhodamine B was up to 92.7% by it. The degradation processes of Rhodamine B,Rhodamine 6G,methyl violet and methyl green all accorded with the first order reaction kinetics equation.