掺杂改性TiO_2/AC与TiO_2/ACF的制备及其对气相甲苯的降解性能

Preparation of TiO_2/AC and TiO_2/ACF via Doping Modification and Photocatalytic Activities of the Products for Gas-Phase Toluene Degradation

以钛酸丁酯为前驱体,采用溶胶-凝胶法制备了Fe、N离子共掺杂的、以活性炭(AC)和活性炭纤维(ACF)为载体的TiO2/AC和TiO2/ACF光催化剂.采用扫描电镜、X射线衍射仪、紫外-可见光分光光度计等对催化剂样品进行了表征.选取甲苯为模型化合物进行光催化降解实验,研究了催化剂制备过程中离子掺杂量、抑制剂种类、焙烧温度、载体种类以及循环使用次数对催化剂活性的影响.结果表明:TiO2在ACF上的分散效果好于在AC上;TiO2以颗粒状镶嵌在AC孔隙内、以膜状包覆在ACF表面,所制备的光催化剂均以锐钛矿相存在;Fe、N离子共掺杂实现了催化剂的可见光响应;以冰醋酸为抑制剂、N和Fe离子掺杂量均为8%(摩尔分数)、500℃下焙烧2 h时,所得的TiO2/ACF光催化剂对气相甲苯的降解活性最高,循环使用效果最好.

Photocatalysts TiO2/AC and TiO2/ACF codoped with Fe and N irons were prepared via the sol-gel method, with butyl titanate as the precursor and, respectively, with activated carbon （AC） and activated carbon fiber （ACF） as the support. The products were then characterized by means of SEM, XRD and UV-Vis. Moreover, the influences of ion-codoping amount, inhibitor species, calcination temperature, carrier species and reuse times on the photocatalytic activities of the catalysts were experimentally investigated, with toluene as a model contamination. The results indicate that （ 1 ） the dispersive effect of TiO2 on ACF is better than that on AC ; （2） TiO2 embeds into AC pores in the form of paricle but coats ACF surface in the form of film, and the two products are both in an anatase phase ; （3） the codoping of Fe and N ions significantly enhances the adsorption of visible light ; and （4） after a sintering for 2h at 500 ℃ with acetic acid as the inhibitor, the prepared TiO2/ACF with an ions dosage of 8% possesses the highest photocatalytic activity for gas-phase toluene degradation even if it has been reused for many times.