宽光谱吸收薄膜光电极的构建及其光催化水体净化研究

Heavy metal ions and organic compound contaminated wastewater is very common and very difficult to purify. A novel recyclable photocatalytic material with broadband absorption spectra, high quantum efficiency and high activity surface/interface is expected to simultaneous decompose the organic matter and achieve the catalytic reduction of heavy metal ions from waste water. Based on the preliminary studies , we plan to design and build a photocatalytic material with a composite structure, eg. semiconductor│electric connection layer│semiconductor to separate the photo-generated carriers. By using film photoanode combined with a porous conductive polymer film as the cathode, the oxidation of organic matter while simultaneously reduction of heavy metal ions away from the active surface of the catalytic material can be realized , which avoid the inactivation of the catalytic material caused by heavy metal deposition onto the photocatalysts surface. And also can solve the recycling difficulties which conventional powdered hotocatalytic materials commonly exsit. The main work mainly include: to design, fabricate and characterize the derived photocatalytic materials; Explore the microstructure control method; Study different degradation laws of different organic pollutants and the photoreduction mechanism for different heavy metal ions; Investigate the interface reaction mechanism and laws and then reveal the reduction rule of heavy metal ions and the degradation mechanism of organic pollutants. Our research can provide a scientific basis and theoretical foundation for environmental remediation by the use of clean energy and also beneficial to the development of green and efficient environment materials.

重金属离子和有机物复合污染水体最为常见且最难治理，宽光谱、高光量子效率、高活性表/界面的光催化材料可望在降解有机物的同时，同步实现对重金属离子的催化还原。拟构建半导体│电联接层│半导体复合结构的光催化材料，有效分离光生载流子，利用现代成膜技术制成薄膜光阳极，结合多孔导电高分子膜做阴极，在氧化有机污染物的同时使重金属的还原反应远离催化材料活性表面，避免还原产物沉积导致催化效率降低，并解决常规粉状光催化材料难回收的难题。主要进行宽光谱吸收的光催化材料的设计、制备和表征工作，探索其结构调控方法，研究其对不同有机污染物的降解规律和不同重金属离子的光还原反应机理，进行光催化反应微观界面过程与电极稳定性研究，揭示重金属离子和有机物在光电极表面还原和降解的微观机制和反应规律，为利用清洁能源进行污水处理和环境修复提供基础。

能源短缺和环境污染是当前人类所面临的重大挑战。光催化技术能够利用太阳光催化许多相关的化学反应，是未来生产清洁能源和环境修复的理想方法。本项目基于能级匹配的原则，开发出一系列具有宽光谱响应、高载流子分离效率、高活性与高量子效率的光催化材料，并广泛应用于重金属固定、有机物降解、水裂解制氢、二氧化碳还原等领域。本项目主要解决两个关键科学问题：1）精细设计宽光谱响应光催化材料组成结构，探究其合成原理、生长机制，揭示调控催化材料理化性质（光吸收能力、能带/电子结构和电子转移）的规律和机制；2）精细设计纳米甚至原子尺度催化位点，结合理论计算从原子乃至分子水平揭示新型宽光谱响应催化材料的电子结构、活性位点、载流子分离效率与其催化性能的内在关联，阐明相关光催化体系的催化机制。部分研究结果已发表在JACS等顶级期刊上。相关研究对于完善和发展宽光谱高效光催化材料理论/途径并发展光催化水/空气净化能源短缺和环境污染是当前人类所面临的重大挑战。