Abstract A facile, eco-friendly approach is proposed for fast preparation of a partially reduced graphene oxide/carbon nanotube/iron/silver hybrid (rGO/CNT/Fe/Ag) under ambient conditions. The partial reduction and exfoliation of GO, the ultrafast growth of CNT on the rGO surface, and the formation of AgNPs occurred simultaneously within 10–30 s using a domestic microwave oven. The morphology and structure of the rGO/CNT/Fe/Ag hybrid are discussed in detail, and a possible formation mechanism is proposed. The obtained rGO/CNT/Fe/Ag hybrid exhibited high catalytic activity for reduction of 4–nitrophenol (4–NP) by NaBH4 with a kinetic rate constant of 14.66 × 10−3 s−1, a normalized rate constant of 1884.31 s−1 × g−1 and a turnover frequency of 33.6 h−1 due to the synergistic effect of all consisting components in the hybrid. With a high surface area, GO serves as a good substrate for immobilization of more AgNPs, whereas rGO/CNT with a high electrical conductivity promoted the electron transfer in the reduction of 4–NP. AgNPs were the catalytic active sites for the reduction of 4–NP, whereas the presence of FeNPs and Fe3C facilitate for recovering and recycling the catalyst easily. Moreover, the rGO/CNT/Fe/Ag hybrid maintained high catalytic activity and stability after five cycles and easy reusability by an external magnet.

中文翻译：

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还原氧化石墨烯/碳纳米管/铁/银杂化物的简便快速合成及其在4-硝基苯酚催化还原中的增强性能

摘要 提出了一种简便、环保的方法，用于在环境条件下快速制备部分还原的氧化石墨烯/碳纳米管/铁/银杂化物（rGO/CNT/Fe/Ag）。使用家用微波炉，GO 的部分还原和剥离、碳纳米管在 rGO 表面的超快生长以及 AgNPs 的形成同时发生在 10-30 秒内。详细讨论了 rGO/CNT/Fe/Ag 杂化物的形态和结构，并提出了可能的形成机制。获得的 rGO/CNT/Fe/Ag 杂化物对 NaBH4 还原 4-硝基苯酚 (4-NP) 表现出高催化活性，动力学速率常数为 14.66 × 10-3 s-1，归一化速率常数为 1884.31 s-由于混合体中所有组成成分的协同效应，1 × g-1 和 33.6 h-1 的周转频率。由于表面积大，GO 作为固定更多 AgNPs 的良好底物，而具有高电导率的 rGO/CNT 促进了 4-NP 还原过程中的电子转移。AgNPs 是还原 4-NP 的催化活性位点，而 FeNPs 和 Fe3C 的存在有助于轻松回收和回收催化剂。此外，rGO/CNT/Fe/Ag 杂化物在五次循环后仍保持高催化活性和稳定性，并且易于通过外部磁铁重复使用。