黑色TiO^(2)/活性炭复合材料的制备及其光催化净化甲醛性能

Preparation of black TiO^(2)/activated carbon and its photocatalytic purification performance for formaldehyde

甲醛是最受关注的室内气态污染物之一。传统甲醛吸附类净化材料存在寿命短、二次污染、废弃物难处理等问题。以钛酸四丁酯为钛源,通过溶胶-凝胶法在氩气气氛下煅烧制备了黑色二氧化钛,采用TEM、XRD、DRS、XPS等技术手段表征了材料的物理、化学、光学特性,并利用连续流表面式光催化反应系统测试黑色TiO^(2)的甲醛净化性能。结果表明,黑色TiO^(2)存在表面无序层和氧空位等特征,并在紫外和可见光区域表现出更高的吸光度和更窄的带隙,紫外光下的甲醛单通净化效率可达78%。通过将活性炭与黑色TiO^(2)复合,可进一步提升材料的甲醛净化效率,并得到在不同流速下活性炭的最佳负载量。黑色TiO^(2)/活性炭与负载高锰酸钠的活性氧化铝经过16 h的长期性能测试对比,前者累计净化量是后者的1.5倍,且并未出现效率的衰减。本研究可为光催化技术在室内甲醛净化领域的应用提供参考。

Formaldehyde is one of the most widely concerned indoor gaseous pollutants.Traditional adsorption-based purification materials have the problems of short life-time,potential of secondary pollution and difficulty of waste disposal.In this study,black titanium dioxide was prepared by sol-gel calcination with tetrabutyl titanate as titanium source under argon atmosphere.The physical,chemical and optical properties of the prepared materials were characterized by TEM,XRD,DRS and XPS.Its formaldehyde purification performance was tested by continuous flow surface photocatalytic reaction system.The results show that black TiO^(2)has the characteristics of disordered surface layer and oxygen vacancy,and exhibits higher visible light absorbance and narrower band gap.Its single-pass purification efficiency of formaldehyde under ultraviolet light can reach 78%.By combining black TiO^(2)with activated carbon,the formaldehyde purification efficiency was further improved,and the optimal load of activated carbon at different flow rates were obtained.The long-term performance of black TiO^(2)/activated carbon and activated alumina loaded with potassium permanganate was compared for 16 hours,and the results show that the cumulative purification capacity of the former is 1.5 times that of the latter,and there is no efficiency decay.This study provides reference and comparison on material level for the application of photocatalytic technology in indoor formaldehyde purification.