A NiO/MnO2 nanostructure for efficient reduction of 4-nitrophenol and chromium(vi)

Abstract

This study presents the synthesis of a NiO/MnO₂ nanostructure designed for the efficient reduction of 4-nitrophenol and Cr(VI). The catalyst underwent comprehensive characterization using various physical techniques including XRD, TEM, FT-IR, XPS, BET, etc. Additionally, theoretical investigations were conducted to elucidate the mechanism of 4-nitrophenol reduction to 4-aminophenol over the NiO/MnO matrix. Moreover, XRD and FT-IR analysis unveiled the subtle changes in morphology after the 8th run, providing insights into the catalyst's longevity and potential for sustainable catalysis. The reaction demonstrated an impressive conversion rate of approximately 99% for 4-nitrophenol reduction within 10 min, and complete reduction of Cr(VI) in just 6 min utilizing the NiO/MnO₂ nanostructure.