【摘要】 以TiCl4为钛源,采用酸催化水解法合成了TiO2前驱体,在NH3/N2气氛中经程序升温处理制得不同N掺杂量的TiO2可见光响应催化剂.以苯酚为模型物,考察了催化剂在可见光及紫外光区的催化活性.采用X射线衍射、紫外-可见漫反射光谱、傅里叶变换红外光谱、扫描电镜和低温氮物理吸附对光催化剂的晶相结构、光谱特征和表面结构进行了表征.结果表明,掺杂N后锐钛矿TiO2的可见光催化活性显著提高,在500℃焙烧5 h制得的催化剂在可见光区及紫外光区均表现出最高的光催化活性.N掺杂对TiO2的晶粒大小、比表面积和晶相结构影响不大.适量N掺杂可在TiO2表面形成Ti-O-N键,形成了新的能级结构,使催化剂的吸收带边红移至490~550 nm;同时该结构也可有效提高TiO2的紫外光催化活性.更多还原

【Abstract】 The N-doped visible-light response nanosize TiO₂ photocatalyst was prepared using the acid-catalyzed hydrolysis method followed by calcination in an NH₃/N₂ atmosphere.The photocatalytic activity of the prepared N-doped TiO₂ for phenol degradation was investigated under visible and UV light irradiation,respectively.X-ray diffraction,UV-Vis diffuse reflectance spectroscopy,Fourier transform infrared spectroscopy,scanning electron microscopy, and N₂ adsorption were used to characterize the catalyst.The results showed that the N-doped TiO₂ catalyst displayed obvious photocatalytic activity under visible light irradiation.The N-doped TiO₂ catalyst calcined at 500 ℃ for 5 h exhibited the highest activity in both UV and visible light regions. N-doping showed little effect on the crystalline structure,surface area,and crystal size of TiO₂.The（Ti-O-N） bond formed on the surface of the catalyst could extend the absorption edge to the visible light region（490-550 nm） and also benefit the photocatalytic acitivity of TiO₂ under UV irradiation.The newly formed（TiO-N） bonds and the reduced agglomeration of the single crystals were mainly responsible for the high activity of the N-doped TiO₂ in both UV and visible light regions.更多还原