具有多级孔结构TiO2/C块体材料的构筑及其可见光催化净化室内空气的研究

In the current research, the modified TiO2 with hierarchical porous structure exhibit small specific surface area, poor recycle and reuse performance for powder and low utilization efficiency of space light for plane films. Aiming at the present problems, the project intends to adopt the carbon foam with large specific surface area and certain strength as a carrier to prepare a TiO2/C monolithic photocatalytic composite. Thereof, the modified TiO2 with hierarchical porous structure is introduced on the surface of foam struts using surfactants as structure-directed agents through the evaporation-induced self-assembly (EISA) route. Because the open three-dimensional reticular structure guarantees the utilization efficiency of film as high as possible, and the majority of the substrate and the intermediates species are adsorbed onto the carbon foam surface which maintains high activity of the TiO2, the photocatalytic performance of the TiO2/C composite material will be enhanced. In the project, the key issues are focused on understanding of the formation mechanism of TiO2 hierarchical porous structure and controlling of the photocatalytic performance of TiO2/C. According to the research of the project, the influence of the preparation methods, modified routes and microstructure on photocatalytic purification performance of indoor air will be revealed, the synergistic catalytic effect of porous carrier and porous modified TiO2 will be clarified, and the theoretical model of the relationship between the structure and the performance of TiO2/C will be established. By combining controllable modulation of hierarchical porous structure and modified ways of TiO2, preparation methods of the TiO2/C with high photocatalytic properties will be developed.

针对目前多级孔改性TiO2存在比表面积小、粉末结构不易回收与再利用、平面薄膜结构对空间光线利用率低的问题，本项目提出选用具有一定强度的高比表面积泡沫碳作为载体，利用溶剂蒸发诱导自组装的方式在其骨架表面构筑具有多级孔结构的改性TiO2，制备出TiO2/C 块体光催化复合材料。通过泡沫骨架的三维网格结构增加光催化剂的空间光线利用率，借助载体对污染物形成主要吸附保持多级孔改性TiO2高催化活性，促进复合材料在光催化性能方面的提升。在该项目的研究中重点解决TiO2多级孔结构的形成机制与TiO2/C块体材料光催化性能调控的问题。通过本项目的研究，将揭示制备方法、改性方式和微观结构对室内空气催化净化性能的影响规律；明确多孔载体与多级孔改性TiO2结合的协同催化效应；建立TiO2/C光催化材料结构-性能关系理论模型；并根据TiO2改性与多级孔结构的可控调制，发展高性能TiO2/C光催化剂的普适制备方法。

针对目前多级孔TiO2存在比表面积小、粉末结构不易回收与再利用、平面涂层结构对空间光线利用率低的问题，本项目采用含有纤维素纤维的滤纸、纤维素纸和脱脂棉作为碳源合成出具有多级孔结构的TiO2/C块体光催化复合材料。实验结果表明：通过调节载体的形貌与合成工艺，对块体光催化材料的结构与性能有显著影响。利用滤纸制备的具有有序介孔结构的多孔碳为载体，提高了光催化复合材料的比表面积和染料吸附能力，增加了TiO2在碳材料表面的暴露面积，提升了材料的光催化性能。利用纤维素纸为模板水热合成出的透明复合材料为载体，引入石墨烯或二次碳获得的透明自支撑光催化复合材料，扩展了光的响应范围，促进了光生电子-空穴对的分离，改善了透明载体碳化后的光催化能力。同时，通过对该载体在空气中煅烧获得的透明自支撑TiO2薄膜，也表现出优良的染料去除能力。借助于可再生的脱脂棉为载体，制备出具有异质结构的复合光催化材料，并呈现出良好的催化性能。通过本项目的研究，揭示了制备方法、复合方式和微观结构对材料催化净化性能的影响；明确多孔载体与多级孔TiO2结合的协同催化效应，为新型TiO2块体光催化材料开发及其性能优化提供实验基础和理论依据。