TiO2/ACF复合材料的Sol-Gel法制备及其对苯的去除性能

以钛酸四丁酯为钛源，采用改进溶胶凝胶法合成TiO₂前驱体；采用浸渍提拉法将TiO₂前驱体负载在活性炭纤维(ACF)表面制得TiO₂/ACF复合材料.采用X射线衍射（XRD）、扫描电镜（SEM）、低温液氮吸附等对TiO₂/ACF复合材料晶相结构、表面结构等进行了表征.在静态自制光催化反应装置中紫外光照射条件下，以高浓度（2926.5mg/m³）气态苯考察TiO₂/ACF对气相有机污染物的去除性能，以气相色谱质谱（GC-MS）检测中间产物种类与分布.结果表明：TiO₂于ACF表面形成完整薄层，随负载次数增加，TiO₂/ACF比表面积下降；TiO₂薄层变厚、开裂，甚至脱落.400 ℃煅烧时TiO2已完全转变为锐钛矿相，随煅烧温度升高，锐钛矿型TiO₂晶粒尺寸变大，至700℃时开始有金红石相生成.负载2次，400 ℃煅烧TiO₂/ACF复合材料TiO₂/ACF-400-2表现出最高活性.TiO₂/ACF对苯的去除过程中未检测到毒性较大的酚、醌类中间产物.

Heterogeneous Photocatalytic Oxidation Removal of Gaseous Benzene over TiO2/ACF Composite Prepared by Improved Sol-Gel Method

TiO₂/ACF composite was prepared by improved sol gel method using Ti(OBu)₄ as titanium source. TiO₂ precursor was loaded on activated carbon fiber (ACF) by dip-coating method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and N₂ (77K) adsorption were used to characterize the obtained composite. High concentration gaseous benzene in a static mode photocatalytic reactor was used as model compound for photocatalytic activity test. Gas chromatograph mass spectrum (GC-MS) was used for intermediates identification. The results show that TiO₂ can form perfect thin film on ACF surface. With the increase of dip coating times, surface area of TiO₂/ACF decrease, thickness of TiO₂ film increase, then split and even fall off. Complete anatase can be formed for the sample calcinated at 400℃ and phase transformation of anatase to rutile occurrs at 700℃. The crystal size of TiO₂ decrease with the increase of calcination temperature. The sample of TiO₂/ACF-400-2 calcinated at 400℃ and dip-coated twice exhibits the highest activity for benzene removal. Intermediate analysis result reveals that no toxic of phenol and quinine compound is detected.