将活性炭负载与N掺杂有效结合, 采用酸催化水解法在粉状活性炭(AC)表面合成TiO2前驱体, 在NH3/N2气氛中程序升温处理制得N掺杂TiO2-xNy/AC(TON/AC)光催化剂. 以苯酚为模型物, 考查了TON/AC紫外光区、可见光区及太阳光下催化活性以及分离性能、使用寿命. 采用XPS、XRD、DRS、FTIR、SEM、低温氮物理吸附对光催化剂的表面特征、吸光特性、晶相结构等进行表征. 结果表明, N以阴离子形式进入TiO2体相并置换晶格中的O, 适量N掺杂的TON/AC在紫外光区、可见光区及太阳光下均表现出较高的活性. N掺杂在TiO2表面生成Ti--O--N键, 形成新的能级结构, 使催化剂的吸收红移至450～550nm, 诱发TiO2可见光催化活性. AC负载可降低TiO2团聚体的尺寸, 增加催化剂比表面积, 为光催化降解提供高浓度环境, 从而提高光催化效率同时还可改善催化剂分离性能, 提高催化剂使用寿命.
An efficient visible-light response composite photocatalyst TiO2-xNy/AC was prepared by calcination of the mixture of TiO2 precursor made by acid catalyzed hydrolysis method and actived carbon (AC) in NH3 /N2 atmosphere. Photocatalytic activity was investigated through the photocatalytic degradation of phenol. The separability of TON/AC was determined by gravity
sedimentation. X-ray photoelectron spectroscope, X-ray diffraction, diffuse reflectance spectroscope, Fourier transform infrared spectroscope, scanning electron microscope and N2 adsorption isotherm were used for catalyst characterization. The results show that anion N is incorporated into TiO2 lattice and substitutes part of O. TON/AC with suitable N-doping
exhibits high activity under ultraviolet light, visible light and solar light irradiation. Also, TON/AC exhibits better decantability and less deactivation. Doped-N can form a new band gap above the valence band of TiO2 which can extend the adsorption edge to 450--550nm. In addition, Actived carbon support is beneficial to the high dispersion and large surface area of N-doped TiO2.
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