LaMnO3/GA复合材料活化PMS降解四环素的性能和反应机制探究

Investigation of the performance and reaction mechanism of tetracycline degradation by LaMnO3/GA composites activated PMS

  • 摘要: 本研究采用溶胶凝胶法和水热法制备了石墨烯气凝胶(GA)负载的LaMnO3复合催化剂,研究了其对过一硫酸盐(PMS)降解四环素(TC)的催化性能。采用SEM、TEM、XPS、拉曼光谱等手段对样品的形貌结构、元素组成和化学形态进行了表征,结果显示构成了LaMnO3/GA复合催化剂。实验结果表明,与LaMnO3纯样相比(降解率为58%),LaMnO3/GA25复合材料活化PMS降解TC的催化性能可提高至83%以上。这种增强效果可归因于GA的引入,加快了电荷的迁移速率并提升了活性位点的电荷浓度。自由基捕获试验验证了O2, 1O2, •OH作为活性物质在TC降解过程中的重要性。此外,通过探究LaMnO3/GA25/PMS体系对多种无机阴离子(如\textH_\text2\textPO_\text4^- , \textSO_\text4^2- , Cl, Urea, \textHCO_\text3^- )和腐殖酸(HA)的抗干扰活性以及和循环使用性能,证明了LaMnO3/GA25/PMS体系用于复杂水体中污染物处理的可行性,并为充分利用锰矿资源解决环境污染问题提供了新的思路。

     

    Abstract: Graphene aerogel (GA)-loaded LaMnO3 perovskite-type oxides were prepared by sol-gel and hydrothermal methods and their catalytic performance for the degradation of tetracycline (TC) by peroxymonosulfate (PMS) was investigated. SEM, TEM, XPS, and Raman spectroscopy were employed to analyze the morphological structure, elemental composition, and chemical morphology. Characterization results showed the successful preparation of LaMnO3 and LaMnO3/GA crystalline phase heterojunction. The experimental results indicated that, when compared with the pure LaMnO3 (58% degradation rate), the catalytic performance of the LaMnO3/GA25 composites for the PMS activation for TC degradation improved to be more than 83%. This enhancement was mainly attributed to GA complexation, which promotes the charge transfer rate and increases the charge concentration at the reactive sites. The vital roles of •OH and SO4 were certified by free radical trapping assays. In addition, the catalytic activity of the LaMnO3/GA25/PMS system in complex aqueous (HA, \textH_\text2\textPO_\text4^- , \textSO_\text4^2- , Cl, Urea, \textHCO_\text3^- ) environments were also explored. This work demonstrated the feasibility of the LaMnO3/GA25/PMS system for wastewater treatment and provided a novel way to make full use of manganese resources to solve the problem of environmental pollution.

     

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