Controllable preparation and photocatalytic performance study of Ag@AgBr/MgAl-LDH
Ag@AgBr/MgAl-LDH可控制备及光催化性能研究

摘要

本研究探索Ag@AgBr/MgAl-LDH复合材料光催化降解有机污染物的潜力，采用水热法制备有不同AgBr变性的复合材料，借助X射线折射、扫描电镜和紫外-可见漫反射光谱等多种手段研究其结构、形貌与光学性能，结果显示，当亚甲基蓝在可见光下2小时内降解超78%时，复合材料光催化性能最佳。为了解复合材料光催化分解机理，开展淬灭实验，分解过程主要由超氧自由基形成决定，经5次光催化反应，Ag@AgBr/MgAl-LDH催化剂仍保持高催化效率与稳定性能，分析研究说明，AgBr引入有效提高复合材料对可见光反应性，MgAl-LDH层状结构助于电子分离，提升光催化降解整体效率。本研究关于Ag@AgBr/MgAl-LDH复合材料在废水处理中的应用，为可见光条件下有效分解有机污染物提供新视角与支持，材料制备技术及性能优化的复合催化剂Ag@AgBr/MgAl-LDH有望在环境管理与水处理中发挥关键作用。

Abstract

This study explores the photocatalytic degradation potential of Ag@AgBr/MgAl-LDH composite materials for organic pollutants. The hydrothermal method was used to prepare composites with different AgBr transformations, and their structure, morphology, and optical properties were studied using X-ray diffraction, scanning electron microscopy, and UV-visible diffuse reflectance spectroscopy. The results show that when methyl blue is degraded by over 78% within 2 hours under visible light, the photocatalytic performance of the composite material is optimal. To understand the photocatalytic decomposition mechanism of the composite material, quenching experiments were conducted. The decomposition process is primarily determined by the formation of superoxide radicals. After five photocatalytic reactions, the Ag@AgBr/MgAl-LDH catalyst still maintains high catalytic efficiency and stability. Analysis indicates that the introduction of AgBr effectively enhances the reactivity of the composite material to visible light, while the layered structure of MgAl-LDH aids in electron separation, improving the overall photocatalytic degradation efficiency. This study on the application of Ag@AgBr/MgAl-LDH composite materials in wastewater treatment provides a new perspective and support for the effective degradation of organic pollutants under visible light conditions. The preparation technology and performance optimization of the composite catalyst Ag@AgBr/MgAl-LDH are expected to play a key role in environmental management and water treatment.