In recent decades, 4-nitrophenol has become one of the most dangerous substances due to its harmful effects on the environment and the human body. Therefore, the reduction of 4-nitrophenol is necessary to reduce health and environmental impacts. This research presented a novel method for preparing CoMnO (a= 2, and b= 4)/MWCNT nanocatalyst to reduce 4-nitrophenol in the presence of NaBH. However, the high electronic conductivity of MWCNT and the active sites of cobalt and manganese in the nanocatalyst surface exhibited a critical role in nanocatalyst activation for the reduction of 4-nitrophenol in the presence of NaBH. The prepared nanocatalyst has advantages, including easy fabrication, excellent performance, recyclability, and cost-effectiveness, distinguishing it from other nanocatalysts. The fabricated nanocatalyst showed the highest reduction rate of 4-nitrophenol (97.8%) within 10 min. The results displayed that the 4-nitrophenol reduction in the presence of CoMnO/MWCNT was better than alone- CoMnO, corroborating the synergistic impact of MWCNT with metal oxides. Meanwhile, the nanocatalyst was recycled during five runs to reduce 4-nitrophenol without decreasing catalyst activity. The present research can be an excellent example of the design of nanocatalysts based on metal oxides with carbon materials to reduce 4-nitrophenol to 4-aminophenol.

中文翻译：

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使用 CoMnaOb（a= 2，b= 4）/MWCNT 纳米催化剂将 4-硝基苯酚还原为 4-氨基苯酚的实用方法

近几十年来，4-硝基苯酚因其对环境和人体的有害影响而成为最危险的物质之一。因此，减少4-硝基苯酚对于减少健康和环境影响是必要的。该研究提出了一种在 NaBH 存在下制备 CoMnO (a= 2, b= 4)/MWCNT 纳米催化剂还原 4-硝基苯酚的新方法。然而，多壁碳纳米管的高电子电导率以及纳米催化剂表面的钴和锰活性位点在 NaBH 存在下还原 4-硝基苯酚的纳米催化剂活化中发挥着关键作用。所制备的纳米催化剂具有易于制备、性能优异、可回收和成本效益等优点，与其他纳米催化剂不同。所制备的纳米催化剂在10分钟内表现出最高的4-硝基苯酚还原率（97.8%）。结果表明，CoMnO/MWCNT 存在下的 4-硝基苯酚还原效果优于单独的 CoMnO，证实了 MWCNT 与金属氧化物的协同作用。同时，纳米催化剂在五次运行中被回收，以减少 4-硝基苯酚，而不会降低催化剂活性。目前的研究可以作为设计基于金属氧化物和碳材料的纳米催化剂将4-硝基苯酚还原为4-氨基苯酚的一个很好的例子。