【作者】 黄煜；

【导师】 刘湘； 郭建锋；

【作者基本信息】 三峡大学 ， 材料工程（专业学位）， 2021， 硕士

【摘要】 锰氧化物是一种低毒性、低成本而且地球上含量丰富的过渡金属氧化物,通常包括α-、β-、γ-和δ-MnO₂四种不同的晶体结构。其中氧化锰八面体分子筛（OMS-2）属于α-MnO₂,存在Mn²⁺、Mn³⁺和Mn⁴⁺三种价态的锰离子,具有优异的氧化还原性能,近年来得到了广泛地研究。高级氧化技术（AOPs）作为一种绿色环保、操作简单、应用广泛地废水处理技术,引起了研究人员们极大地研究兴趣,然而AOPs目前仍然存在金属离子易浸出、成本高、催化剂效率较低等缺点。因此对OMS-2进行修饰,用于活化过一硫酸氢钾复合盐（PMS）降解有机污染物具有重要意义。本论文分别采用浸渍法和前掺杂法制备了CuO_x/OMS-2和M-OMS-2（M=Fe、Co、Ni、Cu、Ag、Zn）。此外,还发展了一种新颖的、绿色环保的、无KMnO₄参与的OMS-2合成路线。然后采用透射电子显微镜（TEM）、N₂吸附/脱附等温线（BET）、X射线衍射（XRD）、X射线光电子能谱（XPS）等对催化剂的形貌、结构以及化学态进行了表征。最后,构建了CuO_x/OMS-2/PMS、M-OMS-2/PMS和OMS-2-CA/PMS三种催化体系,并分别研究了这些体系对有机染料、硝基化合物、抗生素以及双酚A的降解效果,得出以下主要结论:（1）与传统法制备的OMS-2相比,CuO_x/OMS-2具有更高的Rh B降解活性,这主要是因为Cu与Mn之间的协同作用能够促进电子转移,从而提升其催化活性。不同染料的降解实验以及不同硝基化合物的还原实验表明,CuO_x/OMS-2对降解不同染料以及硝基化合物还原均具有优异的催化活性。最后,CuO_x/OMS-2催化剂被成功循环10次,催化性能没有明显下降,证明了CuO_x/OMS-2具有优异的可循环性和稳定性。（2）成功制备了不同金属掺杂的OMS-2催化剂,通过有机染料降解实验表明,金属掺杂均能提升OMS-2的降解性能,其中Co和Ni的提升效果最好,Ag的最差。自由基淬灭实验结果表明降解过程中存在SO₄^·-、·OH和¹O₂,其中¹O₂是最主要的活性物种。另外,五次循环后的Ni-OMS-2催化剂仍然保持着良好的催化活性,证明了Ni-OMS-2具有良好的可循环性和稳定性。（3）发展了一种无KMnO₄参与的OMS-2合成路线,与传统的回流法相比,这种方法更加绿色环保。另外,与OMS-2/PMS体系相比,OMS-2-CA-450/PMS体系对有机染料、抗生素和双酚A均有较好的降解性能。自由基淬灭实验和EPR结果都证明了自由基过程(O₂^·-、SO₄^·-、·OH)和非自由基过程（¹O₂）共同存在,而且非自由基过程对降解起主要作用。最后通过Rh B的五次循环实验也表明了,OMS-2-CA-450具有良好的稳定性和可循环性。更多还原

【Abstract】 Manganese oxides are low toxicity,low cost and abundant transition metal oxides on Earth,includingα-、β-、γ-andδ-MnO₂ four different crystal structures.Among them,manganese oxide octahedral molecular sieve（OMS-2）belongs toα-MnO₂,which has been widely studied in recent years due to the co-existence of Mn²⁺、Mn³⁺and Mn⁴⁺and excellent redox properties.Although AdvancedOxidation Processes（AOPs）is considered as wastewater treatment technology for environmental-friendly,simple and widely application,there are still many disadvantages about metal ions of easy-leach,high cost and low catalyst efficiency.Therefore,it is of great significance to modifyOMS-2 for activation of PMS degradation organic pollutants.In this paper,CuO_x/OMS-2 and M-OMS-2（M=Fe、Co、Ni、Cu、Ag、Zn）are prepared by wet-impregnation and pre-incorporation method.Moreover,a novel,green and KMnO₄-free procedure to synthesizeOMS-2 are also being developed.Then the morphology,structure and chemical state ofOMS-2 are characterized by transmission electron microscopy（TEM）,N₂adsorption-desorption isotherms（BET）,X-ray diffraction（XRD）and X-ray photoelectron spectroscopy（XPS）.Finally,CuO_x/OMS-2/PMS,M-OMS-2/PMS andOMS-2-CA/PMS catalytic system are constructed to studied the degradation efficiency of organic dyes,nitro compounds,antibiotics and bisphenol A,resulting in the following main conclusions:（1）Compared toOMS-2 prepared by conventional methods,CuO_x/OMS-2 has higher Rh B degradation activity,due to the synergistic effects between Cu and Mn can promote electron transfer and enhancing its catalytic activity.The different experiments of degradation of organic dyes and reduction of nitro compounds indicate that CuO_x/OMS-2 has excellent catalytic activity.Finally,the catalyst has been successfully reused 10 times without significant decrease in catalytic activity indicates that CuO_x/OMS-2 has excellent recyclability and stability.（2）The different metal dopedOMS-2 catalysts are successfully prepared by pre-incorporation method and the results of organic dyes degradation shows that metal doped can improve the degradation performance ofOMS-2,among which Co and Ni is the best improvement effect while Ag is worst.The radical quenching experiments proved that the SO₄˙^-,·OH and ¹O₂ existed in the degradation processes and the ¹O₂ is dominant active oxygen species.In addition,the catalyst has been successfully reused 5 times without significant decrease in catalytic activity indicates that the catalyst has excellent recyclability and stability.（3）Compared with traditional method,we develop a novel and KMnO₄-free procedure to synthesizeOMS-2 which is more green and environmental friendly.Moreover,compared withOMS-2/PMS system,OMS-2-CA/PMS has a better degradation performance to organic dyes,antibiotics and bisphenol A.The radical quenching test and EPR analysis proved that radical（O₂˙^-,SO₄˙^-and˙OH）and non-radical（¹O₂）processes both existed and the latter dominantly contributed to the degradation.Finally,the five recycle of Rh B degradation show thatOMS-2-CA-450 has remarkable recyclability and stability.更多还原