表面微区电场调控对光催化净化室内低浓度有机污染物的机理研究

The various diseases caused by indoor air pollution have seriously threatened the health of the human body. Taking effective measures to eliminate pollution is a hot topic in the field of environmental protection. For the contradiction between the low decomposition rate and the requirement of high purification rate of low concentration organic pollutants by photocatalytic technology, this project intends to control the electric field by the local electric field and the ferroelectric polarization on the surface micro-area of TiO2 nanomaterials. Using formaldehyde and toluene as a probe, we systematically study the enrichment, migration and photodegradation of low concentration organic pollutants. Development of nano-material surface control technology for rapid and efficient removal of low concentration organic pollutants under complex indoor environment conditions. It provides the theoretical basis for the photocatalytic purification of low concentration organic pollutants.

室内空气污染所引发的各种病症已严重威胁人体健康，采取有效措施消除污染是环保领域研究热点。针对光催化技术净化低浓度有机污染物的低分解速率与高净化速率要求间的矛盾，本项目拟通过局域电场和铁电极化对TiO2纳米材料表面微区进行电场调控，以甲醛、甲苯等污染物为探针，系统研究低浓度有机污染物表面富集、迁移以及光降解途径，发展适用于复杂室内环境条件下低浓度有机污染物快速、高效去除的纳米材料表面调控技术，为低浓度有机污染物光催化净化提供理论基础。

针对室内空气中低浓度有机污染物的污染现状，本项目通过局域电场和铁电极化对TiO2纳米材料表面微区进行电场调控。选择高稳定、廉价、无毒的TiO2光催化剂，增强低浓度有机污染物在催化剂表面富集性能，同时提升对光的利用率并减少电子-空穴复合，提高光催化效率。取得了基础研究的系列成果。(1) 通过压电和光催化协同，可以触发铁卟啉/二硫化钼催化剂生成更多的活性自由基。铁卟啉/二硫化钼中压电效应明显，二硫化钼和铁卟啉之间的Fe-S连接促进了光生电荷在两种物质之间的传输。通过改变卟啉中心的金属或使用其他的压电材料，拓展了压电和光催化效应的协同作用。(2) 通过静电纺丝使铁电材料自发极化，这对VOCs物理吸附性能大幅度提升。其次，PVDF有效促进TiO2的电荷分离能力，大幅度提升二氧化钛光催化性能，进一步可制备具有自清洁特性的高效VOCs降解复合膜。(3)铁电极化介孔PbTiO3@TiO2核壳结构对光催化降解甲苯性能极大增强，实现包裹层厚度的可控调变，并进一步提高反应活性。