Abstract The bimetallic Zn/Co zeolitic imidazole frameworks (ZnCo-ZIFs) were successfully synthesized by a simple solvothermal method at room temperature. Silver elements were afterward doped onto the bimetallic frameworks to form Ag/ZnCo-ZIFs via a facile impregnation method in acetone solvent. The as-synthesized material was used as a heterogeneous catalyst for the removal reaction of Congo red (CR) and malachite green (MG) in the presence of hydrogen peroxide (H2O2). Effects of catalyst dosage, H2O2 concentration, initial concentration of the contaminants, reaction temperature, and reaction time were conducted in this work. The results showed that more than 94% and 98% removal of CR and MG were, respectively, achieved within 45 and 30 min. The presence of Ag also enhanced the removal efficiency of CR and MG. The main mechanism of removal reaction of the organic contaminants could be oxidation via hydroxyl radicals. Moreover, the catalytic activity of the material remained over 90% after four recycling cycles. Due to the efficient reactivity as well as high stability, Ag/ZnCo-ZIFs can be a potential heterogeneous catalyst to remove hazardous dyes from aqueous solution.

中文翻译：

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在过氧化氢存在下使用非均相 Ag/ZnCo-ZIF 催化剂从水溶液中去除刚果红和孔雀石绿

摘要 采用简单的溶剂热法在室温下成功合成了双金属 Zn/Co 沸石咪唑骨架（ZnCo-ZIFs）。然后通过在丙酮溶剂中的简便浸渍方法将银元素掺杂到双金属骨架上以形成 Ag/ZnCo-ZIF。合成的材料用作非均相催化剂，用于在过氧化氢 (H2O2) 存在下去除刚果红 (CR) 和孔雀石绿 (MG) 的反应。在这项工作中，研究了催化剂用量、H2O2 浓度、污染物初始浓度、反应温度和反应时间的影响。结果表明，在 45 和 30 分钟内分别实现了 94% 和 98% 以上的 CR 和 MG 去除率。Ag 的存在也提高了 CR 和 MG 的去除效率。有机污染物去除反应的主要机制可能是通过羟基自由基氧化。此外，该材料的催化活性在四次循环循环后仍保持在 90% 以上。由于高效的反应性和高稳定性，Ag/ZnCo-ZIFs 可以成为一种潜在的多相催化剂，用于从水溶液中去除有害染料。