Department of Chemical Engineering, University of Pretoria, Pretoria, 0002, South Africa.
Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
Environ Sci Pollut Res Int. 2024 Feb;31(8):11857-11872. doi: 10.1007/s11356-024-31921-1. Epub 2024 Jan 15.
In this study, the photocatalytic activity of nanomaterials Ag/AgX (X = Cl, Br, I) is reported. Highly efficient silver halide (Ag/AgX where X = Cl, Br, I) photocatalysts were synthesized through a hydrothermal method. The samples were characterized using a range of techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) to check their structural, morphology, textural and optical properties. In addition, the photocatalytic activity of photocatalysts was evaluated through the degradation of 2,4-dichlorophenol (2,4-DCP) under UV and visible light irradiation. XRD analysis confirmed the presence of a single-phase structure (pure phase) in the synthesized photocatalysts. SEM micrographs showed agglomeration with a non-uniform distribution of particles, which is a characteristic of surfactant-free precipitation reactions in aqueous media. The Ag/AgBr photocatalyst exhibited the best degradation efficiency, resulting in 83.37% and 89.39% photodegradation after 5 h of UV and visible light irradiation, respectively. The effect of catalyst loading, initial solution pH, and 2,4-DCP concentration was investigated for the best-performing Ag/AgBr photocatalyst. The degradation kinetics were best described by the pseudo-first-order Langmuir-Hinshelwood model. The photocatalytic capacity of Ag/AgBr decreased by 50% after five reuse cycles. SEM images revealed heightened levels of photodegradation on the catalyst surface. The study proved the feasibility of using simple synthesis methods to produce visible light active photocatalysts capable of degrading refractory phenolic pollutants in aqueous systems.
本研究报告了纳米材料 Ag/AgX(X=Cl、Br、I)的光催化活性。通过水热法合成了高效的银卤化物(Ag/AgX,其中 X=Cl、Br、I)光催化剂。使用 X 射线衍射(XRD)、扫描电子显微镜(SEM)和 Brunauer-Emmett-Teller(BET)等一系列技术对样品进行了表征,以检查其结构、形貌、结构和光学性质。此外,通过在 UV 和可见光照射下降解 2,4-二氯苯酚(2,4-DCP)来评估光催化剂的光催化活性。XRD 分析证实了合成光催化剂中存在单相结构(纯相)。SEM 显微照片显示出团聚现象,颗粒分布不均匀,这是在水介质中无表面活性剂沉淀反应的特征。Ag/AgBr 光催化剂表现出最佳的降解效率,在 5 h 的 UV 和可见光照射后分别达到 83.37%和 89.39%的光降解。研究了最佳性能的 Ag/AgBr 光催化剂的催化剂负载量、初始溶液 pH 值和 2,4-DCP 浓度的影响。降解动力学最好由准一级 Langmuir-Hinshelwood 模型描述。Ag/AgBr 的光催化能力在五次重复使用循环后下降了 50%。SEM 图像显示催化剂表面的光降解程度更高。该研究证明了使用简单的合成方法生产能够降解水体系中难处理酚类污染物的可见光活性光催化剂的可行性。