水解沉淀法制备氮掺杂TiO_2可见光光催化剂

为拓展TiO2可见光的响应范围,以氨水为氮源,在常温条件下采用水解沉淀法制备了氮掺杂TiO2粉末。以X射线衍射、紫外-可见漫反射吸收光谱和X射线光电子能谱等对TiO2进行了表征。对可见光照射下的光催化活性进行了测试,并考察了煅烧温度及掺杂量等对光催化活性的影响。结果表明:氮掺杂致使TiO2吸收边带向可见光区偏移,在降解亚甲基蓝的实验中表现出良好的可见光催化活性;随煅烧温度的增加,氮摩尔分数增加,晶粒增大,可见光催化活性减弱;煅烧温度为400℃,氮的摩尔分数为2%时制备样品的光催化活性最高。

N-doped TiO_2 visible-light responsive photocatalysts prepared by hydrolysis precipitation method

With a view to extending titanium dioxide (TiO_2) respondence to the range of visible light, the N-doped TiO_2 photocatalysts were prepared based on the hydrolysis precipitation method at room temperature with ammonia as the nitrogen source. The as-prepared samples photocatalysts were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance pectroscopy (Uv-vis DRS) and X-ray photoelectron spectroscopy (XPS). Photocatalytic activity was tested under the irradiation of visible light, and the impacts of the calcination temperature and doping on photocatalytic activity were examined.The results showed that the absorption band edge of TiO_2 shifted to the visible light region upon nitrogen-doping. Visible light catalytic activity was observed in the experiment of the decoloration of methylene blue. With the increase of calcination temperature or the nitrogen content, grain size increased, and visible light catalytic activity decreased. The samples had the highest photocatalytic activity with the calcination temperature of 400 ℃ and N/Ti mole ratio of 2%.