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采用NH3-H2气氛两步热处理法制备氮掺杂氧缺陷TiO2,用X射线粉末衍射、N2吸附BET法、X射线光电子能谱、元素分析、电子自旋共振谱、紫外可见漫反射光谱和荧光光谱等技术对样品的晶相结构、表面化学状态、氮含量、氧缺陷位种类及含量、光吸收性能和光生载流子的分离效率等性质进行了表征,研究了H2气氛中不同热处理时间对催化剂性能的影响和催化剂样品在可见光(λ>400 nm)条件下的光催化氧化能力。结果表明,掺氮TiO2催化剂经H2热处理1 h后具有较好的可见光催化活性,对苯的转化率和矿化率分别为66.8%和47.5%,其降解效率高于单掺杂催化剂活性的总和,双掺杂光催化剂活性的提高与氮杂质氧缺陷双光活性中心的协同增强作用有关。
The nitrogen-doped oxygen-deficient TiO2 was prepared by NH3-H2 atmosphere two-step heat treatment. The structure of TiO2 was investigated by X-ray powder diffraction, N2 adsorption BET method, X-ray photoelectron spectroscopy, elemental analysis, electron spin resonance spectrum, UV-visible diffuse reflectance spectroscopy and fluorescence Spectroscopy and other techniques were used to characterize the crystal structure, surface chemical state, nitrogen content, the type and content of oxygen defect sites, the light absorption properties and the separation efficiency of photo-generated carriers. The effects of different heat treatment time in H2 atmosphere The effect of the catalyst performance and the photocatalytic oxidation ability of the catalyst sample under visible light (λ> 400 nm). The results show that the nitrogen-doped TiO2 catalyst has good visible light catalytic activity after H2 heat treatment for 1 h, and the conversion and mineralization rate of benzene to benzene are 66.8% and 47.5%, respectively. The degradation efficiency is higher than the sum of single-doped catalyst activity , And the improvement of the activity of the doubly doped photocatalyst is related to the synergistic enhancement effect of the bi-photoactive center of the oxygen vacancy of the nitrogen impurity.