新型异质结复合磁性光催化剂的功能化组装及其光催化还原CO2的研究

探索如何控制大气中CO2的总量和积极应对能源危机，已成为全球可持续发展的战略问题。在太阳能驱动下利用光催化材料将CO2转化为可再生碳氢燃料，实现碳循环利用，是理想的CO2资源化方案。但传统意义的半导体催化剂存在量子效率低、难以回收、吸附能力差等缺点，本项目以磁性核壳介孔氧化硅为载体，通过层层自组装的方法，将具有光催化活性组分与介孔组分相复合，构筑“磁性核-介孔硅-半导体”三元异质结复合磁性光催化剂，实现光催化剂在介孔孔道内的高分散和小粒径沉积。将该材料应用于光催化还原CO2合成甲醇反应中，评价光催化材料的光催化活性，磁可分离性和稳定性，获得高效、稳定的异质结复合光催化剂。在性能评价的基础上，研究异质结复合磁性光催化剂的结构、组成以及各组分对催化性质的影响，揭示光催化剂性能与结构之间的内在规律。本项目的研究为半导体材料在CO2的综合利用提供实验依据，也为环境治理中CO2的资源化提供新途径。

Nowaday the problem of global warming and energy crisis have aroused considerable public concern, which is dominantly due to the increasing levels of CO2 emissions from fossil fuel consumption. Managing CO2 emissions is one of the largest political and technical challenges for the sustainable development currently. One promising approach involves the photocatalytic reduction of CO2 into hydrocarbon fuel. One of the biggest challenges preventing the large scale development of photocatalysts for CO2 reduction is the problems such as the general photocatalyst in adsorption, agglomeration, and difficult to reuse. Hence, the new strategies are required to further promote the photocatalytic reduction of CO2. In this project, magnetic core-shell mesoporous material was synthesized by modified hydrothermal method. Heterostructural semiconductor with high dispersion and small particle size were deposited on mesoporous via layer by layer assembly. The photoreduction of CO2 was characterized to investigate the photoactivity of the materials. The photocatalytic activity, magnetic separability and stability are evaluated. The influence of mesoporous structure, chemical composition, physical and chemical properties on the photoactivity and adsorption stability is also studied. Based on the experimental results and theoretical calculation, we explore the relationship between the photocatalysts performance and its structure, to reveal the mechanism of photocatalytic CO2 reduction. Our work provides a novel strategy for designing of new functional efficient semiconductor-based photocatalysts for the reduction of CO2. This work can potentially be used at long term storage sites to convert CO2 into chemicals with industrial value, which ensure the long-term economic and social stability as well as the security and environmental sustainability of the world at large.