人工光合作用新材料的研发和机理研究

To minimize the negative impact of CO2 emission, and to restore the balance of carbon cycle in the ecosystem are the foremost mission of scientists in the contemporary world. The current chemical community focuses on two separate pathways: one is the carbon capture and sequestration and the other is the catalytic CO2 conversion. However, this proposal presents an innovative strategy to tackle the urgent environmental issue by coupling both pathways together. Specifically, we will develop a novel composite material based on porous metal-organic frameworks (MOFs) with high CO2 selectivity and titanium oxide (TiO2) nanoparticles with solar catalytic activity. This material is able to capture CO2 effectively and then utilize solar energy and water to convert CO2 into useful chemicals. The successful execution of this project will offer a practical solution to minimize the cost of CO2 reduction, and open a pathway to the idealized artificial photosynthesis. We plan to achieve our goals through the following steps: 1. Adjust the bandgap of the TiO2 nanoparticles and enhance its catalytic activity under solar radiation; 2. Joint TiO2 and MOF at nanometer scale and promote charge transfer at the interfaces; 3. Design proper reaction conditions for CO2 capture and conversion and evaluate the efficacy of the catalyst; 4. Employ advanced characterization techniques to investigate the structures and reaction mechanisms. The principal investigator has extensive research experience in the synthesis and characterization of MOF materials. In particular, the group possesses the unique capabilities of the world-class solid-state NMR facility in Zhejiang University, with which the group will pursue the fundamental understanding of the structure-property relationship and provide guidance to the R&D effort.

减少二氧化碳CO2排放对环境的影响，维持自然界碳循环的平衡是科学界亟需解决的重要课题。目前化学学科的研究主要集中在CO2的分离捕捉以及CO2的转化两个独立领域。本项目提出一条全新途径：将CO2捕捉与催化转化合二为一，利用可见光和水为原料，将CO2转化为有机原料。具体来说，本项目将设计由金属有机框架材料MOF和纳米二氧化钛TiO2组成的新型复合材料，利用MOF的选择性吸附和TiO2的光催化活性，实现CO2的高效捕捉和转化。此方法的实现将大大降低减少碳排放的成本，从而达成人工光合作用的理想目标。本项目主要研究目标包括：1. 对TiO2元素掺杂使其具有可见光催化活性。2. 促进复合材料界面的电荷转移。3. 设计合理的反应条件并对催化性能进行评估。4. 对材料结构和反应机理进行深入研究。申请人在MOF材料的研究方面有丰富经验；尤其本课题组掌握的世界领先的固体核磁技术将为新材料研发提供宝贵信息。

减少二氧化碳CO2排放对环境的影响，维持自然界碳循环的平衡是科学界亟需解决的重要课题。本项目尝试利用可见光和水为基础，将CO2转化为可利用的碳原料。具体来说，本项目设计、搭建并优化了气固相光催化装置，使其适用于二氧化碳还原实验。此装置成功实现了在燃烧尾气条件下由CO2到CO或CH4的转化。我们制备了多种新型基于二氧化钛的催化材料，并使其在紫外或可见光照下产生了明显的二氧化碳还原效果，效果优于或接近参照物P25。同时，我们也探索了多种具有CO2吸附效果的金属有机框架材料（MOF），为两者进一步结合打下基础。我们利用固体核磁、透射电镜等分析技术对材料进行了全面的表征，并对光吸收，分子吸附等性质进行了研究。我们深入探讨了材料的构效关系，推进了二氧化碳光催化还原机理的理解。