银/一维银系材料/钴酸镍纳米片多维度磁性异质结光催化剂构筑及降解酚类内分泌干扰物研究

Phenolic endocrine disruptors, such as Bisphenol A and its substitute, Bisphenol S, are new types of organic pollutants, which are harmful to the human and animal. How to effectively remove the phenolic endocrine disruptors in aqueous solution has been a challenge in water pollution control field. By in-situ construction of high stability and activity of photocatalyst with magnetic separation characteristic, the project is aimed at using this novel photocatalyst for degradation of bisphenol A and bisphenol S. Firstly, one-dimensional silver-based semiconductors Ag2V4O11 and AgInS2 will be in-situ self-assembled on the surface of NiCo2O4 magnetic ultrathin nanosheets respectively. Further, multidimensional magnetic heterojunction photocatalysts Ag/Ag2V4O11/NiCo2O4, Ag/AgInS2/NiCo2O4 systems with magnetic separation and high performance and stability can be fabricated by in-situ chemical reduction or photoinduced reduction method. Using phenolic endocrine disruptors as the degradation objects, the correlation between the photocatalytic performance and the structure as well as the composition and loading amount and loading method will be greatly concerned. Moreover, the degradation pathway of the target compound will be proposed in details. The decay of activity mechanism will be also investigated. Overall, by the implementation of the project, the experimental and theoretical basis will be studied throughout for the novel photocatalysts, which will be applicable to degrade and remove phenolic endocrine disruptors in water.

酚类内分泌干扰物如双酚A、双酚S是一类具有危害的典型新型污染物，如何高效去除水环境中该类污染物是水污染控制领域面临的新挑战。本项目拟通过原位构筑高稳定性和活性兼具有磁分离特性的光催化剂，利用其高效光催化降解双酚A及双酚S。首先将一维结构的Ag2V4O11和AgInS2分别原位负载在二维超薄磁性NiCo2O4纳米片表面，进一步通过原位化学还原或者光致还原制备出多维度磁性异质结光催化剂Ag/Ag2V4O11/NiCo2O4和Ag/AgInS2/NiCo2O4。以水环境中典型酚类内分泌干扰物为目标物，系统研究光催化剂组成、微结构、负载量、负载方式等因素对光催化稳定性和活性的影响规律，阐明构效关系；研究目标物在此催化体系上降解矿化的过程和机理；探索光催化剂在循环使用过程中的活性衰减与失效机理。本项目的实施为设计该类光催化剂应用于水环境中典型酚类内分泌干扰物的高效降解及去除奠定实验及理论基础。

开展高效去除水环境中典型的酚类内分泌干扰物（双酚A、双酚S）的技术，在水污染控制领域具有重要的科学意义与应用前景。本项目制备出多种高活性兼具有磁分离特性的Ag2V4O11/NiCo2O4，Ag/Ag2V4O11/NiCo2O4，AgIn5S8/UIO-66-NH2等异质结光催化剂，制备的这些催化剂具有较大的比表面积，利用异质结光催化剂各组分间的协同作用，能够有效抑制光生电子-空穴的复合，提高光催化活性，分别实现了高效光催化氧化降解双酚S和光催化还原Cr6+。同时，在研究中总结异质结的构建方法，通过对催化剂的形貌结构进行调控，结合p-n异质结、表面等离子体效应、Z型体系等能带工程设计策略，制备出高效的p-Ag2S/n-BiVO4 p-n异质结，Ag/p-AgBr/n-BiVO4表面等离子体p-n异质结，多维g-C3N4/SnS2和Ag3VO4/BiVO4 三维花球状Z型异质结等光催化材料。通过XRD、BET、SEM、TEM等表征手段证明制备的光催化剂具有较大的比表面积，有利于吸附有机物；紫外-可见吸收光谱显示催化剂在可见光区域显示出增强的光吸收强度；荧光光致发光光谱和光电流等表征表明异质结结构能够大幅度增加载流子的寿命；通过光催化降解实验系统研究光催化剂的组成、微结构、负载量等因素对光催化活性的影响，实现了在可见光下高效光催化氧化双酚S，双酚A和光催化还原重金属离子Cr6+等环境污染物；与此同时，还通过气相色谱-质谱联用技术鉴定出双酚S、双酚A和四环素等有机污染物的光催化降解产物，据此提出相应的光催化机理。本项目的研究工作成功制备出p-n异质结、具有表面等离子体效应的p-n异质结、Z型异质结等光催化材料，为此类材料应用于重金属离子的高效还原以及酚类内分泌干扰物的光催化氧化降解，提供一定的理论和实验依据。