Critical role of copper ions and active hydrogen for fast reduction of 4-nitrophenol using CuS mesh

Abstract

This study investigated the catalytic performance of CuS mesh in the reduction of 4-nitrophenol (4NP) to 4-aminophenol (4AP) under various conditions using sonication-treated CuS mesh. While CuS mesh exhibited a reaction-rate constant of 0.082 min⁻¹, sonication-treated CuS mesh achieved a significantly higher constant of 0.512 min⁻¹. The reduction rate decreased under oxygen-bubbling conditions, confirming the importance of active hydrogen species. This study also explored the effects of different metal ions, including Cu, Ag, Au, Ni, Pd, Pt, Co, Zn, Pb, and Cr. Among them, metals such as Cu, Ag, Au, Pd, and Pt, which exhibit positive standard reduction potentials favorable for electron transfer, were found to effectively catalyze the 4NP reduction. These findings suggest that optimizing the structural configuration of the CuS mesh and leveraging the dual catalytic roles of Cu ions and nanoparticles can help develop more efficient catalysts for environmental remediation and chemical synthesis.