TiO2基空心光催化材料的原位表面剪裁及其CO2还原性能与机理

The advance in highly active and selective photocatalysts is a key scientific challenge in producing solar fuels from photocatalytic reduction of carbon dioxide (CO2). In order to overcome the drawbacks of currently available TiO2-based photocatalysts in terms of low photocatalytic activity and inferior photocatalytic selectivity, this project aims to construct advanced TiO2-based photocatalysts with improved activity and selectivity towards photocatalytic reduction of CO2 to solar fuels, especially methane (CH4) and methanol (CH3OH), via in-situ surface tailoring of hollow TiO2 photocatalyst with a variety of structural advantages, which contribute to the synergetic optimization of "adsorption centers" and " catalytically active centers". The key parameters and controlling law in dominating the surface structure and chemistry of TiO2-based hollow photocatalysts will be clarified. Moreover, synergetic effects of surface host-guest structures and chemistry in affecting photocatalytic CO2 reduction performances will be thoroughly investigated, and the relationship between surface structures and chemistry of as-prepared TiO2-based nanocomposites and their photocatalytic activity and selectivity in targeted photocatalytic reduction of CO2 and the corresponding underlying mechanisms will be disclosed. The outcomes of this project will innovate advanced technology for design and synthesis of TiO2-based composite nanomaterials, will advance highly active and selective host-guest composite photocatalyst systems, will enrich the basic knowledge of artificial photosynthesis.

开发高性能半导体光催化材料体系是光催化CO2还原制太阳燃料领域的关键科学问题。针对现有TiO2光催化材料活性低与选择性差的缺陷，本项目提出，针对CO2向CH4,CH3OH等高品质燃料的光催化转化，在空心光催化材料诸多结构优势的基础上，开拓原位表面结构与化学剪裁策略，从优化“吸附中心”与"催化活性中心"两大光催化功能模块着手，改善光催化CO2还原活性与选择性，构筑先进TiO2基太阳燃料光催化材料。揭示TiO2空心结构合成控制与表面剪裁一体化设计制备的关键参数与控制规律。深入研究主客体表面结构与化学特征的光催化协同效应，建立表面结构与化学影响光催化 CO2 还原活性与选择性的关系模型与内在机制。该项目旨在革新先进TiO2基光催化材料的的设计制备方法，开发新型高活性高选择性主客体复合光催化材料体系，丰富人工光合成的理论知识。

光催化CO2还原转化为太阳燃料是最有前途的绿色低碳技术。针对光催化CO2向CH4、CH3OH等太阳燃料的定向转化活性低与选择性差两大关键科学难题，本项目主要从以下三个方面开展研究工作：。 .（a）以优化CO2吸附中心为切入点，发展了TiO2等多孔空心光催化材料的表面结构与化学特性剪裁调控方法，制备了具有优异CO2吸附能力的Au修饰TiO2多孔空心光催化剂等高效光催化CO2还原材料体系。初步揭示了CO2主要吸附活性中心与关键转化路径，提升了光催化CO2定向转化为甲烷、甲醇等高品质太阳燃料的利用效率，阐释了“光吸收、电荷传递、CO2吸附活化与催化还原”等核心光催化过程一体化协同调控机制，为开发先进光催化CO2还原材料体系和高效CO2资源化利用技术提供理论支撑与实验参考。.（b）基于“CO2捕集-光催化转化”双功能集成策略，克服传统CO2吸附剂对光吸收、电荷传递等光催化过程的负面遮阻效应，开发了g-C3N4与ZnO等低维纳米光催化材料表面原位构筑透明导电吸附中心的新方法，制备了Pt@ZIF-8共修饰ZnO纳米棒光催化剂等集“CO2捕集与光催化转化”双功能于一体的新型高效光催化CO2还原材料体系，揭示了ZIF-8的表面钝化效应及其对光吸收、电荷传递、CO2吸附活化与催化还原的影响规律与机制，显著提升光催化CO2定向转化为甲烷、甲醇等高品质太阳燃料的利用效率，为发展绿色低碳新技术与CO2资源化利用技术提供科学依据与技术支撑。.（c）在原研究计划基础上，针对“水氧化半反应效率低”的瓶颈问题，开发双功能Z-型复合光催化材料体系，建立新型“CO2资源化与有机污染物降解”耦合光催化系统，初步探讨了同步有机污染治理与碳资源循环利用的可行性，进一步提升光催化CO2定向转化为甲烷、甲醇等太阳燃料的能源效率，为CO2资源化利用与人工光合成技术发展开拓新思路。