This study reveals the feasibility of exploring highly efficient, cost-effective, and stable green adsorbents for the treatment of contaminated water. Here silver nanoparticles (AgNPs) were immobilized onto nanosheets of graphene oxide (GO) through in situ reduction process using green tea aqueous extract. GO reduction to reduced graphene oxide (rGO) and AgNPs decoration on rGO also occurred simultaneously. The impacts of the extract concentration, contact time, and temperature on the synthesis process have been investigated. The synthesized nanocomposites were examined by XRD, FTIR, Raman, SEM, TEM, and TGA. The GO nanosheets were decorated by AgNPs with a crystalline structure and an average particle size of 25 ± 3 nm. The temperature and the extract concentration were considerably affecting the type of the resulting nanocomposites. The GO/Ag nanocomposites were formed at room temperature (27 °C) using different extract concentration (2-18% (v/v)), while the rGO/Ag nanocomposite was formed only at a higher temperature (95 °C) with higher extract concentration (18%). The methylene blue (MB) dye was picked as a water pollutant to explore the adsorption ability of the nanocomposites. The adsorption behavior of the GO/Ag nanocomposites was examined under diverse factors (MB concentration, adsorbent dosage, pH, and contact time) to achieve optimization. The adsorption data concurs with Langmuir isotherm giving maximum adsorption up to 633 mg g-1. Adsorption kinetics demonstrate good pseudo-second-order compliance. Spontaneous and endothermic nature of adsorption was affirmed via thermodynamic parameters. The nanocomposites could be utilized as eco-friendly and reliable adsorbents in wastewater treatment, as a result of their exceptional productivity and reusing potential.

中文翻译：

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使用绿色固定化银纳米颗粒在氧化石墨烯和还原的氧化石墨烯片材上通过一锅合成有效地处理亚甲蓝。

这项研究揭示了探索高效，低成本和稳定的绿色吸附剂来处理污水的可行性。在这里，通过使用绿茶水提取物的原位还原过程将银纳米颗粒（AgNPs）固定在氧化石墨烯（GO）的纳米片上。GO同时还原为氧化石墨烯（rGO）和在rGO上修饰AgNPs也同时发生。研究了提取物浓度，接触时间和温度对合成过程的影响。通过XRD，FTIR，拉曼，SEM，TEM和TGA检查合成的纳米复合材料。GO纳米片由具有晶体结构且平均粒径为25±3 nm的AgNP修饰。温度和提取物浓度显着影响所得纳米复合材料的类型。GO / Ag纳米复合材料是在室温（27°C）下使用不同的提取物浓度（2-18％（v / v））形成的，而rGO / Ag纳米复合材料仅在较高温度（95°C）下形成。更高的提取物浓度（18％）。选择了亚甲基蓝（MB）染料作为水污染物，以探索纳米复合材料的吸附能力。在多种因素（MB浓度，吸附剂量，pH和接触时间）下检查GO / Ag纳米复合材料的吸附行为，以实现优化。吸附数据与Langmuir等温线一致，最大吸附量可达633 mg g-1。吸附动力学表现出良好的拟二级顺应性。通过热力学参数确定了吸附的自发性和吸热性。