水中环境内分泌干扰物的吸附富集光催化降解联合研究

TiO2 is one of the most promising photocatalysts because of its outstanding oxidative power and photochemical stability. However, slow reaction rate,poor solar efficiency has hindered the commercialization of this technology. In this project, we intent to synthesize a novel visible light driven composite TiO2 nanowire photocatalyst with high activity and hight adsorption capacity by a graphene and graphite-like C3N4 (g-C3N4) double modification. The visible light photocatalytic activity of the composite photocatalys could be generated by g-C3N4; the photocatalytic activity of the composite photocatalyst could be significant enhanced due to the rapid electron and hole transpoting property of these delocalized conjugated π materials. Moreover, the large specific surface area of graphene can enhance the adsorption capacity of the composite photocatalyst. We intent to reveal the essential relation between graphene modification, g-C3N4 modification and the photocatalytic performance of the as-prepared composite photocatalyst. Reveal the environmental endocrine disruptors (P-chlorophenol) adsorption mechanism of the as-prepared composite photocatalyst. Reveal the photocatalytic degradation mechanism and transformation process of P-chlorophenol. The implementation of this project has important scientific significance on promotion of integration and development of the functional material preparation and environmental decontamination.

TiO2具有强的氧化能力和良好的化学稳定性，是最具有应用前景的一类光催化材料。针对其量子效率低；不能吸收可见光；粉末催化剂难回收等缺点，我们设想在柔性衬底（碳布）上构建石墨烯和类石墨相氮化碳（g-C3N4）修饰的TiO2纳米线阵列，通过石墨烯和g-C3N4的共轭大π键可以实现光生载流子的快速导出，极大提高光催化效率，并实现催化活性向可见光区的扩展；石墨烯大的比表面积有利于提高该复合光催化材料的吸附性能。本项目拟系统考察在石墨烯和g-C3N4修饰下催化剂结构，光化学光物理性质及光催化活性的变化，阐明各部分的协同作用机理；系统研究该复合光催化材料对环境内分泌干扰物（四氯酚）的吸附机制；探讨四氯酚的光催化降解机理和转化过程。该项目的实施可以推动功能材料制备与环境净化研究的发展，具有重要的研究意义。

光催化技术因为其氧化能力强，反应条件温和，能利用太阳能等优点，而成为污染物治理领域的研究热点。针对目前污染物治理难点，制备具有吸附富集和光催化降解功能的光催化剂，阐明内分泌干扰物的降解和转化过程对实际废水的处理具有重要指导意义。本项目成功地在柔性衬底（碳布）上制备了C3N4/TiO2核壳纳米线阵列，获得了可再生、具有吸附富集功能，可见光驱动的新型光催化材料；g-C3N4的共轭大π 键结构可以实现光生载流子的快速导出，极大提高光催化效率，并实现光催化活性向可见光区的拓展；C3N4/TiO2核壳纳米线阵列具有良好的接触界面和高的稳定性。项目系统研究了C3N4/TiO2核壳纳米线阵列的优化制备，形貌结构，理化性质以及光生载流子的分离和传输，揭示了光催化活性提高机制。考察了C3N4/TiO2核壳纳米线阵列对内分泌干扰物双酚A的光催化及光电催化降解效率、外加偏电压对光电催化活性的影响规律。并通过产物分析，阐明了双酚A的光电催化降解和转化过程。此外，围绕“吸附富集光催化降解有机污染物”这个研究思路，本项目还开发了 CdS填充碳纳米管复合催化剂，既提高了光催化效率，又有效抑制了CdS的光腐蚀。本项目的研究为制备具有吸附富集和光催化降解功能的新型复合材料提供了理论指导和实验依据，有利于光催化技术在环境治理领域的推广应用。