A practical approach for reduction 4-nitrophenol to 4-aminophenol using CoMnaOb (a= 2, and b= 4)/MWCNT nanocatalyst

Abstract

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 CoMnaOb (a= 2, and b= 4)/MWCNT nanocatalyst to reduce 4-nitrophenol in the presence of NaBH4. 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 NaBH4. 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 CoMnaOb/MWCNT was better than alone- CoMnaOb, 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.