纳米TiO_2光催化水泥降解甲基橙的研究

Research on degradation of methyl orange by using nano-TiO_2 photocatalytic cement

光催化剂与建筑材料的结合是光催化领域一个重要的发展方向.文中以添加纳米TiO2的水泥为研究对象,以甲基橙的光催化降解活性为指标,考察了光催化水泥用量、水泥中TiO2的含量、水泥水化龄期以及甲基橙初始浓度对甲基橙降解效果的影响.结果表明,在紫外光照射下,当甲基橙的初始浓度为5 mg/L,光催化水泥用量为3 g/L,水泥中TiO2含量为5%时,光催化效率最高;延长水泥水化龄期,光催化水泥对甲基橙的吸附性能和降解性能均有所下降;提高甲基橙初始浓度,可以增强光催化水泥对甲基橙的吸附性能,当初始浓度达到15 mg/L时,光催化水泥的吸附量可达54.5%.

The combination of photocatalyst and building materials is an emerging direction of develop- ment in the photocatalytic field. In this paper, the photocatalytic activity of nano-TiO2 cement is mea- sured by the degradation efficiency of methyl orange. The influence of the dose of photocatalyst, different TiO2 contents, curing age and the initial concentration of methyl orange on the degradation efficiency of methyl orange are investigated. Experimental results indicate that the optimum photocatalytic efficiency would be achieved under the following conditions： initial concentration of methyl orange at 5 mg/L, pho- tocatalyst dose at 3 g/L, and cement with 5 % TiO2. The adsorption performance and degradation efficiency of photocatalytic cement would decrease with the prolonging of curing age. The adsorption property of photo- catalytic cement is enhanced with the increase of initial methyl orange concentration. The adsorption effi- ciency of photocatalytic cement is up to 54.5 % when the initial concentration is 15 mg/L.