氮掺杂对TiO_2催化剂吸附性能及光催化性能的影响

Influence of N-doping on adsorption and photocatalytic degradation performance of TiO_2 catalysts

以低浓度碱溶剂热法制备钛酸纳米纤维,利用二次水热法掺杂氮元素制得N-Ti O2催化剂;采用X射线衍射和扫描电子显微镜对制备的催化剂进行表征。以亚甲基蓝溶液模拟有机废水,考察氮掺杂量对催化剂吸附性能和光催化性能的影响,揭示吸附性和光催化性能的内在联系。结果表明,掺杂氮元素未改变Ti O2的晶型,但能改变Ti O2晶体尺寸,对其形貌有一定影响,同时显著提高N-Ti O2催化剂的吸附性能和催化活性。氮掺杂量越高,晶粒尺寸越小,比表面积越大,吸附和光催化性能越好。在n(N)∶n(Ti)=1∶1时,Ti O2光催化活性和吸附性能最佳。

The titanate nanofibers was prepared by solvothermal method with low concentration of alkali, and then N-doped TiO2 catalysts were prepared by twice hydrothermal method. The as-prepared catalysts were characterized by X-ray diffraction and scanning electron microscope. Using methylene blue solution as the simulated organic wastewater, the influence of N doping amounts on the adsorption and catalytic performance of the catalysts was investigated, and the inherent connection of adsorption and photocatalytic properties was revealed. The results showed that doping nitrogen could change the crystal size and morphology of TiO2 , but could not change its crystal structure. Furthermore, the adsorption and catalytic activity of N-doped TiO2 catalysts were improved obviously. The higher the amounts of N doping, the smaller the grain size, the bigger the specific surface area and the better the performance of adsorption and photocatalysis. Under the condition of n （N） ： n （Ti） = 1 ： 1, TiO2 photocatalyst possessed the optimal performance of adsorption and photocatalysis.