Removal of organic dyes from wastewater has become an important issue because of their carcinogenic and mutagenic effects. In this study, we prepared Ag-doped ZnO (Ag_ZnO) photocatalysts containing various amounts of Ag (0.05-0.5mol%) by a hydrothermal process followed by calcination at 500 °C and evaluated the photocatalytic degradation of methylene blue (MB) under sunlight irradiation. The incorporation of Ag into the ZnO lattice and the hexagonal wurtzite structure of the prepared catalysts could be confirmed by X-ray photoelectron spectroscopy and powder Xray diffraction analysis. BET analysis shows that the pore volume and pore size was increased with doping Ag into ZnO. The photocatalytic degradation of methylene blue followed a pseudo-first-order kinetics and the rate constant for dye degradation with 0.1% mol Ag was almost three-times bigger than that with bare ZnO. Our study shows that the photocatalytic activity of ZnO toward MB degradation under sunlight can be effectively enhanced by doping with Ag.

中文翻译：

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掺银氧化锌光催化降解亚甲基蓝

由于其致癌和致突变作用，从废水中去除有机染料已成为一个重要问题。在这项研究中，我们通过水热法制备了含有不同量 Ag (0.05-0.5mol%) 的 Ag 掺杂 ZnO (Ag_ZnO) 光催化剂，然后在 500 °C 下煅烧，并评估了阳光下亚甲蓝 (MB) 的光催化降解辐照。通过 X 射线光电子能谱和粉末 X 射线衍射分析可以证实 Ag 掺入 ZnO 晶格和制备的催化剂的六方纤锌矿结构。BET 分析表明，随着将 Ag 掺杂到 ZnO 中，孔体积和孔径增大。亚甲蓝的光催化降解遵循准一级动力学，染料降解速率常数为 0。1% mol Ag 几乎是裸 ZnO 的三倍。我们的研究表明，掺杂 Ag 可以有效增强 ZnO 在阳光下对 MB 降解的光催化活性。