纳米TiO2与活性炭纤维复合降解空气中甲醛

通过Sol—Gel法和超临界干燥手段制备具有网络结构和纳米级粒径的TiO2气凝胶，并使之与活性炭纤维（ACF）复合，经过450℃高温煅烧，即可获得具有较高光催化活性和强吸附性的TiO2／ACF复合材料，用以降解目标污染物甲醛。以钛酸丁酯（Ti（OC4H9）4为原料，乙醇、乙酸和乙酰丙酮为水解催化剂制备醇凝胶，溶胶反应液的配比为Ti（OR）4：EtOH：H20：AcOR：ACACH：20：40：5：0．2：2（体积比，mL）。经超临界流体干燥后，在扫描电镜（SEM）下观察，TiO2在ACF的每根纤维上负载均匀，其粒径大小均匀，尺寸均在40—50nm范围内，具有网络结构，空隙率大。在紫外光的作用下，可在25min内使游离甲醛从6．58mg／m^3降至0．99mg／m^3；甲醛的降解效果依次为：TiO2／ACF1〉TiO2／ACF0〉ACF。

Photocatalytic Degradation of Formaldehyde by a Combination of TiO_2 and Activated Carbon Fibers

Photocatalytic degradation of formaldehyde indoor air was investigated using TiO2 loaded on activated carbon fibers （ACF）. The TiO2 and ACF combination （TiO2/ACF） was prepared by using soakage ACF in sol - TiO2 and the supercfitical fluid CO2 dry process, followed by calcination at 450℃ in vaecum, the TiO2/ACF composite with good photocatalytic actvity may effective eliminate or reduce indoor harmful air - formaldehyde. The tetrabutyl titanate Ti （ OR ）4 was based material, ethanol （EtOH）, water and acetylacetone （ACACH） as chelating reagent, acid （AcOR） as catalyst to controlling sol -gel condition and component. The solution ratio of Ti （OR）4/EtOH/H2O/AcOR/ ACACH/was 20： 40： 5： 0. 2： 2. After the supercritical fluid CO2 dry process, the TiO2/ACF1 with nano - （40 -50nm） and framework was obtained. Through measurement the amount of formaldehyde removal for the TiO2/ACF1 composite was still higher than that TiO2/ACF0 by normal dry and ACF.