石墨烯基复合催化剂非均相类Fenton降解有机污染物的研究

发布时间：2018-06-02 00:38

  本文选题：过一硫酸盐 + 硫酸根自由基　； 参考：《合肥工业大学》2015年硕士论文

【摘要】：本文针对持久性有机污染物难以治理的技术难题,开展以催化材料为核心的新型类Fenton技术研究,围绕类Fenton催化剂的理性设计和基础科学问题,构建基于硫酸根自由基(SO.-)的石墨烯基复合催化剂(Mn3O4-rGO, Co-rGO和Co(OH)2)/PMS耦合催化氧化去除水中有机物,以活性自由基基团生成速率与生成效率为优化指标,设计并制备出新型石墨烯基复合催化剂,揭示了催化剂生长机理和结构控制途径,探明了矿化有机物的反应机理,诠释了催化材料的组成—结构—表/界面性质—催化性能间的构效关系,在新型类Fenton的基础理论和应用两个方面均取得了较好的成绩。本论文的主要研究内容如下所示：(1)以鳞片石墨为原料,采用改进的Hummers法制备氧化石墨,以所制备的氧化石墨作为前驱体,在水溶液中用原位合成技术成功制备了纳米Mn3O4-rGO复合物催化剂,并研究了其活化PMS降解有机污染物金橙Ⅱ的性能。采用FESEM、EDS、TEM、XRD、Raman、XPS和TGA对所制备的催化剂进行相关的表征测试,表征的结果表明Mn304纳米颗粒成功负载到石墨烯表面,Mn3O4-rGO杂化材料中的Mn304纳米颗粒的平均粒径为29.2 nm。催化性能测试表明,常温条件下,浓度为0.5g/L的Mn304-rGO催化剂能在120 min内将30 mg/L的金橙II完全降解。此外,金橙II的降解效率随温度(25-55℃)、pH值(4.0.11.0)PMS浓度(0.25-1.5g/L)的升高而升高,但随金橙II溶液初始浓度(30-90 mg/L)的升高而降低。同时,催化剂在循环4次后仍可在120 min内反应完全,显示出良好的稳定性。(2)以氧化石墨为原料,采用原位合成技术制备出Co-rGO催化剂的前驱体,再通过氢气还原成功制备Co-rGO催化剂,并以此构建了纳米Co-rGO/PMS的新型高级氧化体系。研究发现,在纳米Co-rGO复合物中,Co纳米颗粒与石墨烯的结合在催化活性方面起到了协同作用。与纯Co纳米颗粒相比,纳米Co-rGO复合物对PMS分解反应的催化活性更强,更有利于有机污染物的氧化降解。在相同催化剂(Co-rGO)和PMS(0.2g/L)用量下,Co-rGO/PMS体系中金橙Ⅱ(60mg/L)的降解遵循准一级反应动力学,速率常数k为0.0747 min-1,是Co/PMS体系中表观速率常数k (0.0357 min-1)的2.1倍。(3)采用简单的水热合成法,以葡萄糖为氧化石墨烯的还原剂,成功制备出α-Co(OH)2-rGO的杂化材料,并对利用该催化剂活化PMS降解苯酚的性能进行了研究。催化剂的表征结果表明α-Co(OH)2纳米颗粒随机的、无规律的负载在石墨烯片层上。催化剂的催化性能研究发现,在催化剂浓度为0.02 g/L, PMS浓度为0.5g/L的条件下,α-Co(OH)2-rGO/PMS体系在40 min内对30 mg/L苯酚溶液的降解率达到了99%。当α-Co(OH)2-rGO浓度提高到0.1 g/L,10min即可将等量的苯酚溶液完全降解。最后,利用HPLC技术,检测了α-Co(OH)2-rGO/PMS体系降解苯酚的中间产物,并给出了苯酚降解的机理。
[Abstract]:In this paper, aiming at the technical problems of persistent organic pollutants (pops) being difficult to control, a new type of Fenton technology with catalytic material as its core is developed, which focuses on the rational design and basic science of Fenton-like catalysts. A graphene based composite catalyst based on sulphate radical (SO.-) was constructed for the removal of organic compounds in water by coupled catalytic oxidation of mn _ 3O _ 4-rGO. Co-rGO and Co(OH)2)/PMS. The formation rate and efficiency of active radical groups were taken as the optimization index. A novel graphene based composite catalyst was designed and prepared. The mechanism of catalyst growth and structure control was revealed, and the reaction mechanism of mineralized organic matter was explored. The structure-activity relationship between the composition, structure, surface / interface properties and catalytic properties of the catalytic materials was explained, and good results were obtained in the basic theory and application of the new Fenton. The main contents of this thesis are as follows: (1) using flake graphite as raw material, graphite oxide was prepared by improved Hummers method, and graphite oxide was used as precursor. Nano-sized Mn3O4-rGO complex catalysts were successfully prepared by in-situ synthesis in aqueous solution, and their catalytic properties for the degradation of gold orange 鈪，

本文编号：1966481