环糊精修饰炭基复合光催化剂构筑及对水体除草剂捕获光降解机制研究

For the long-term presence of high concentrations of herbicide contaminants in the water body in Xinjiang, which caused serious environment, human health hazards and other issues. The research is proposed to develop novel cyclodextrin-modified carbon-based composite photocatalysts and study the removal mechanism of the rapid capture and photodegradation for typical herbicides, taking advantage of long duration of sunshine and strong light intensity in Xinjiang. Through the synthesis of binary photocatalyst with special complementary structure-activity function and high visible light response, the mechanism of high visible light response of binary photocatalyst with the relationship between the photocatalytic degradation properties and the structure would be revealed; the interfacial effect and the interaction behavior between the functional groups of the carbon-based materials and binary photocatalyst are to be investigated; the modification effect of cyclodextrin on carbon-based composite photocatalysts and the mass transfer mechanism of the fast and efficient capture for typical herbicides are to be analyzed; the mass transfer-reaction mechanism of the particles on the catalyst surface during photodegradating herbicides by using cyclodextrin-modified carbon-based composite photocatalyst is to be revealed; the coupling relationship between the capture and photodegradation performance for typical herbicides by cyclodextrin-modified carbon-based composite photocatalyst is to be defined; the functional and regulatory mechanism of cyclodextrin-modified carbon-based composite photocatalyst on the fast capture and photodegradation for typical herbicides are to be clarified. Therefore, it possesses a strong theoretical innovation and important application value to develop novel cyclodextrin-modified carbon-based composite photocatalysts for degradation of the typical herbicides in water.

针对新疆水体中长期存在较高浓度的除草剂污染物，造成了生态环境及人类健康的严重危害等问题。利用新疆日照时间长、光照强烈等优势，开展环糊精修饰炭基复合光催化剂构筑及其快速捕获光降解典型除草剂的脱除机制研究。通过合成具有高可见光响应的特殊构效功能互补的二元光催化剂，揭示二元光催化剂高可见光响应机制及其光催化降解性能与结构关系；探讨炭基材料的功能基团与二元光催化剂间的界面效应及作用行为；解析环糊精对炭基复合光催化剂的修饰作用及快速高效捕获典型除草剂的传质作用机制，揭示环糊精修饰炭基复合光催化剂的光降解除草剂过程中催化剂表面粒子的传质-反应历程，明确环糊精修饰炭基复合光催化剂对典型除草剂的捕获性能与光降解性能间的耦联关系；阐明环糊精修饰的炭基复合光催化剂快速捕获光降解典型除草剂的作用机理及调控机制。因此，开展环糊精修饰炭基复合光催化剂降解水体中除草剂具有很强的理论创新性和重要的应用价值。

开展了环糊精修饰炭基复合光催化剂构筑及对水体除草剂捕获光降解机制研究，主要体现如下：.第一、通过采用煅烧法、接枝法等修饰方法，探究了不同环糊种类（α-CD、β-CD、γ-CD），以及不同的修饰顺序对炭基光催化剂材料进行有效的修饰，获得了环糊精修饰炭基复合光催化剂的关键参数，揭示了环糊精修饰炭基复合光催化剂的关键参数以及与光催化剂微观结构的相关性。.第二、通过环糊精修饰在复合光催化剂表面，发现不同环糊精种类、不同修饰比例都对水体中除草剂的去除有直接关系，针对MoS2/g-C3N4复合光催化剂，α-CD、β-CD和γ-CD的修饰均能增强水体除草剂的去除性能，但随着吡喃葡萄糖的聚合数的增加，α-CD、β-CD和γ-CD修饰的光催化剂活性增加。通过表征分析阐明了环糊精修饰的复合光催化剂与光催化活性的构-效关系。.第三、利用β-环糊精修饰g-C3N4，制备了CA-β-CD/g-C3N4/Ag2O、CA-α-CD/g-C3N4/Ag2O和CA-γ-CD/g-C3N4/Ag2O系列复合光催化剂。通过引入改性环糊精，g-C3N4的表面结构及官能团数量得到明显改善，有利于Ag2O附着在其表面，以此形成致密的异质结，有利于缓解银基半导体光腐蚀现象。10:1:1 CA-β-CD/g-C3N4/Ag2O展现出优异的光催化降解性能及循环稳定性，揭示了CA-β-CD修饰g-C3N4的带隙变窄，电子的迁跃距离变短，且与Ag2O形成异质结，有利于电子在界面间转移，提高载流子的分离速率，在模拟太阳光照射下120 min后对草甘膦的降解率为94%。.第四、通过采用乙二醇与乙酸的协同体系，构建了一条快速、绿色的Bi基复合光催化剂的制备关键技术，不仅可以有效解决Bi基复合光催化剂制备过程中需要使用HNO3的诱导晶体成核的问题，而且数量级缩短了反应时间（15min），实现ClCS复合光催化剂可以实现90 min内去除超过98%的草甘膦。乙二醇经过5次循环利用后制备的ClCS-R5复合光催化剂对草甘膦的去除率仍达97%。阐明了在乙二醇与乙酸的协同体系中溶剂与晶体成核的相互作用机制。.该项目的研究结果已发表文章19篇，其中SCI检索17篇，申请中国发明专利5件，培养硕士8名，其中5名研究生获优秀硕士学位论文奖。