石墨烯杂化g-C3N4基有机光催化剂水凝胶净化有机污染物的研究

This project aimed at the present key scientific problems in the photocatalytic treatment of environmental sewage that the visible light utilization efficiency of the photocatalyst and the sewage treatment rate are low, the separation of the catalyst from the solution is difficult. Firstly, the combination and graft copolymerization of the organic semiconductor with g-C3N4 are employed to increase the π-π conjugated structure of the g-C3N4 organic polymer molecules, resulting in the expansion of the visible-light absorption and the improvement of the oxidation ability. Then the graphene-photocatalyst hybrid hydrogel was prepared by the combination of the graphene and the g-C3N4 based organic photocatalyst. The synergistic effect of the adsorption and photocatalysis was realized to decontaminate the organic pollutants by graphene-photocatalyst hybrid hydrogel, and the removal efficiency of the organic pollutants was imporved. The mechanism of the energ bang structure regulation by the π-π bond conjugated structure of the organic compound is revealed. the controllable synthesis mechanism and of the graphene hybrid photocatalysts high specific surface area and network structure was studied and the influence factors of surface functional groups was investigated. The effect of the structure and surface property of the graphene hybrid photocatalysts on the adsorption kinetics and thermodynamics process was studied, and the adsorption mechanism was investigated. The synergistic effect mechanism of the adsorption and in situ photocatalysis was demonstrated. This study lays the theoretical foundation for the designing the novel photocalyst material with the high adsorption, high visible light photocatalytic activity, the high sewage flux set, which can make the adsorption and photocatalysis processes work at the same time.

该项目针对目前光催化处理环境污水中存在的可见光利用率低、污水处理效率低和催化剂难分离等关键科学问题。通过调控有机分子π-π共轭结构方法，在g-C3N4体外复合和体内接枝含有π共轭结构的有机半导体，提高g-C3N4的可见光吸收能力和氧化能力；然后通过石墨烯杂化效应制备出石墨烯杂化g-C3N4基有机光催化剂水凝胶，实现对有机污染物的高效吸附富集-可见光原位光催化降解协同净化，提高有机污染物去除效率。揭示有机半导体共轭结构对g-C3N4能带调控的机理和规律；揭示高比表面积和网络结构的石墨烯杂化光催化剂可控合成机理及表面基团功能化的影响因素；阐明复合水凝胶网络结构和表面性质对有机污染的吸附动力学和热力学过程影响，揭示其吸附机理；阐明复合水凝胶的吸附富集-可见光下原位光催化降解协同作用机理。为设计出具有高效吸附、高可见光光活性、高污水处理通量的集吸附富集和光催化为一体的污水处理新材料奠定理论基础。

该项目针对目前光催化处理环境污水中存在的可见光利用率低、污水处理效率低和催化剂难分离等关键科学问题。创新的设计和制备出了具有高效吸附、高可见光光活性、高污水处理通量的石墨烯杂化复合水凝胶光催化的污水处理新材料。研究发现采用具有共轭结构的有机半导体材料如石墨烯和卟啉等，对g-C3N4光催化材料进行修饰改性，可以大大提高有g-C3N4可见光吸收能力和氧化能力；这主要是由于有机半导体的共轭大π键结构，可增加π电子离域度，两者之间的电荷转移使g-C3N4的HOMO轨道（价带）能量降低，氧化能力增强。利用石墨烯杂化效应制备出一系列石墨烯复合水凝胶光催化材料，该复合水凝胶光催化材料具有较好的使用稳定性和污水处理能力。石墨烯水凝胶作为载体，加速对机物污染物的吸附富集，同时石墨烯的杂化作用也有效地提高光催化材料的电子空穴的分离效率，提高了光催化活性，研究揭示了复合水凝胶的吸附富集-可见光下原位光催化降解协同作用机理。本项目研究为设计出高效、稳定的废水处理新材料奠定理论基础，也为日益严重的环境问题提供了新思路。