One-step fabrication of Fe3O4-Cu nanocomposites: high-efficiency and low-cost catalysts for reduction of 4-nitrophenol

Abstract Transition metal Cu nanocrystals have shown promising prospects for degrading organic pollutants. Herein, high-efficiency Fe3O4–Cu nanocomposites (NCs) have been successfully synthesized though a facile one-step thermal decomposition method. With a turnover frequency of 6.4 min−1, our Fe3O4–Cu NCs (heated temperature: 225 °C) could degrade the 4-nitrophenol in less than 15 s and showed almost unchanged catalytic efficiency (>90%) after recycled reactions up to six times. Furthermore, the influence of the heat treatment on the structure, elemental distribution, magnetic property and catalytic performance of Fe3O4–Cu NCs was investigated. As the temperature increased from 225 °C to 285 °C, the saturation magnetization of Fe3O4–Cu NCs decreased from 7.27 to 26.2 emu/g, owing to the enlarged mass ratio of Fe3O4 nanocrystals: Cu nanocrystals. This work provides the practical design guidance to the large-scale fabrication of high-efficiency and low-cost Fe3O4–Cu NCs catalysts, which shows promising future for degrading the nitro compounds in wastewater.