大尺寸大孔径TiO_2/SiO_2光催化剂的制备及甲醛去除研究

以大孔径SiO2为载体,通过钛酸丁酯溶液的浸渍、原位水解以及高温煅烧制备出大尺寸、大孔径的TiO2/SiO2光催化剂。利用自制空气净化装置对室内甲醛的清除进行研究,分别考察了TiO2的百分含量、紫外光光强、温度、湿度和空气流量等不同条件下TiO2/SiO2光催化剂对除去甲醛效率的影响。结果表明,反应温度从10～50℃依次升高,去除率逐渐下降。在相对湿度为50%,TiO2负载率为55.6%,流量为8 m3/h时,甲醛的最佳除去率达96.5%;经过7周时间的考察,发现TiO2/SiO2光催化剂的催化活性没有明显的下降。

Preparation of large-sized macroporous TiO_2/SiO_2 photocatalyst and photodegradation of formaldehyde

Large-sized macroporous TiO2/SiO2 photocatalyst was prepared through the infiltration of tetrabutyl titanate solution into a novel SiO2 support,subsequent in-situ hydrolysis in the air and calcination at high temperature.The catalyst was used to clean formaldehyde in the air through a self-made experimental apparatus,the cleaning of formaldehyde by the catalyst was investigated under different conditions such as load capacity of TiO2,intensity of ultraviolet light,temperature and humidity of the air,and the rate of air flow.The results showed that the cleaning rate decreased slightly as the temperature raised from 10 ℃ to 50 ℃.Under ultraviolet light radiation,adopting a flow rate of 8 m3/h and relative humidity of 50% the highest degradation rate of formaldehyde reached 96.5% by using a catalyst with TiO2 content of 55.6%.After continuous experiments for a period of 7 weeks,the photocatalytic activity of macroporous TiO2/SiO2 did not decline considerably.