Study on Reduction of 4-nitrophenol by Magnetic Maize Straw Supported with Copper Nanoparticles

Abstract In this work, magnetic maize straw was prepared by the amidation process using renewable maize straw as starting material. After magnetic succinylated maize straw (Mag-S-MS) was mixed with cupric ions aqueous solution, Cu (II) could be captured by the amino and carboxylate groups. Then, the bonded Cu (II) was converted to valuable Cu nanoparticles (Cu NPS). It was characterized by SEM-EDS, XRD, XPS, and TGA, which indicated Cu NPS were formed successfully on Mag-S-MS without self-aggregation and oxidation. The above nanocomposites could be employed as a catalyst for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The effect of the dosage of Cu NPS loaded-Mag-S-MS, the initial concentrations of NaBH4 and 4-NP were investigated, and a possible mechanism was discussed. The catalyst maintained relatively high catalytic activity after five cycle tests. Due to its superparamagnetic nature, it could be quickly collected from the aqueous solution under a magnetic field. These results could provide a method for using agricultural waste in nano catalytic reaction.