有序介孔碳/TiO2的制备及其典型VOCs降解机理研究

Complex VOCs pollutants in air make it difficult to eliminate. In order to quickly and efficiently remove the VOCs pollutants, mesoporous carbon/titania composites are proposed here to embedding highly active TiO2 nanocrystals into the mesoporous carbon frameworks, tailoring the pore structures, surface chemistry as well as controlling the crystal size and crystallinity of TiO2 nanoparticles to facilitate the adsorption-diffusion process of different VOCs within the mesoporous carbon matrix and improve the separation of photo-generated charges and photocatalytic oxidation performance. For the elimination of different types of VOCs pollutants, the following three key issues are aimed to be solved: (1) rapid adsorption of different VOCs pollutants on mesoporous carbon/TiO2 composites, then immediate diffusion to TiO2 active sites, finally photocatalytic oxidation into CO2 and H2O to achieve the separation of adsorption sites and photocatalytic sites at the nanoscale; (2) the synergistic effects of mesoporous carbon and TiO2 on the adsorption capacity and photocatalytic performance; (3) tracking the active species and intermediates produced under light irradiation.

空气中VOCs污染物种类复杂，处理难度大。本项目以实现典型VOCs的快速、高效降解为目标，设计高活性TiO2纳米晶均匀分布在碳骨架的介孔碳/TiO2，进行孔道结构、表面化学性质等方面剪裁，控制TiO2晶粒尺寸及结晶度等参数，调控不同种类VOCs在功能化介孔碳骨架中吸附-扩散过程及光生电荷界面传递，提高其对VOCs污染物的光催化氧化性能。针对不同类典型VOCs污染物消除的特点，着重解决以下三个关键问题：（1）不同VOCs污染物在介孔碳/TiO2复合材料上快速吸附，并在孔道内快速扩散至TiO2活性位点，光催化氧化成CO2和H2O，实现吸附位点与光催化位点在纳米尺度分离；（2）介孔碳与TiO2在污染物吸附与光催化氧化间的协同作用关系；（3）光照下活性物种种类、VOCs降解过程中间产物生成。

空气中VOCs污染物种类复杂，处理难度大。本项目以实现典型VOCs的快速、高效降解为目标，设计高活性TiO2纳米晶均匀分布在碳骨架及其他支撑载体上，进行表面修饰、表面化学性质等方面剪裁，控制光敏性助催化剂的分散性和稳定性，提高本征TiO2光催化剂的可见及紫外光活性，研究不同种类VOCs在功能化TiO2基及钨酸铋光催化剂表面的吸附过程及光生电荷界面传递过程，提高其对VOCs污染物的光催化氧化性能。针对不同类典型VOCs污染物消除的特点，着重解决以下三个关键问题：（1）不同VOCs污染物在光催化剂表面的快速吸附，并采用量子点和纳米簇修饰光催化剂提高其光吸收和电荷捕获能力，实现光催化氧化成CO2和H2O；（2）支撑载体与光催化活性组分在污染物吸附与光催化氧化间的协同作用关系；（3）光照下活性物种种类、VOCs降解过程中间产物生成。