Department of Environmental Engineering, Faculty of Engineering, Gebze Technical University, 41400, Gebze, Turkey; Department of Environmental Engineering, Faculty of Engineering and Natural Sciences, Bursa Technical University, 16310, Bursa, Turkey.
Department of Environmental Engineering, Faculty of Engineering, Gebze Technical University, 41400, Gebze, Turkey.
Chemosphere. 2022 Dec;309(Pt 1):136534. doi: 10.1016/j.chemosphere.2022.136534. Epub 2022 Sep 19.
In this study, a ternary layered double hydroxide containing Zn, Co, and Fe transition metals (ZnCoFe LDH) was developed using a co-precipitation procedure. The as-synthesized photocatalyst was evaluated for its performance in the degradation of methylene blue (MB) under visible light irradiation. The effects of various process conditions including photocatalyst dosage, pollutant concentration, pH, lamp distance, and lamp power were investigated. The ZnCoFe LDH achieved approximately 74% photodegradation efficiency owing to the narrow bandgap of 2.14 eV. The Langmuir-Hinselwood rate constants were calculated as 1.17 min and 3.55 min for photolysis by LED lamp alone and for photocatalysis by LED/ZnCoFe LDH, respectively. The photocatalytic ability of the LDH was attributed to the generation of radical species like OH and O. The photocatalytic degradation intermediates of MB were determined by GC-MS analysis. The catalyst retained its performance throughout seven reuse cycles with only a 4.17% reduction in removal efficiency. The energy per order E of the ZnCoFe/LED process in 180 min treatment time was determined as 5.41 kWh.m. order. This study shows that ZnCoFe LDH has sufficient activity and photostability for long-term application in photocatalytic water treatment.
在这项研究中，使用共沉淀法制备了一种含有 Zn、Co 和 Fe 过渡金属的三元层状双氢氧化物（ZnCoFe LDH）。合成的光催化剂用于在可见光照射下降解亚甲基蓝（MB）的性能评估。研究了各种工艺条件的影响，包括催化剂用量、污染物浓度、pH 值、灯距和灯功率。由于 2.14 eV 的窄带隙，ZnCoFe LDH 的光降解效率约为 74%。单独使用 LED 灯光解和使用 LED/ZnCoFe LDH 光催化的 Langmuir-Hinselwood 速率常数分别计算为 1.17 min 和 3.55 min。LDH 的光催化能力归因于生成了像 OH 和 O 这样的自由基物质。通过 GC-MS 分析确定了 MB 的光催化降解中间体。催化剂在七个重复使用循环中保持性能，去除效率仅降低了 4.17%。在 180 分钟处理时间内，ZnCoFe/LED 工艺的每阶能量 E 确定为 5.41 kWh.m 阶。这项研究表明，ZnCoFe LDH 具有足够的活性和光稳定性，可长期应用于光催化水处理。
