One-Step Green Synthesis of Multifunctional Fe3O4/Cu Nanocomposites toward Efficient Reduction of Organic Dyes

Graphical An Fe 3 O 4 /Cu nanocatalyst that exhibits excellent catalytic performance in the degradation of 4-nitrophenol (4-NP) (the reaction was accomplished within 4 min), rhodamine B (within 3 min), and methylene blue (within 1 min) as well as superior stability (can be reused at least five times) was successfully synthesized through a green one-step solvothermal method with ethylene glycol as reductant and reaction media. Noble-metal-derived functional materials have played indispensable roles in the reduction of dye under aqueous conditions; however, their cost and separation are great limitations on their wider practical applications. Therefore, an alternative preparation of comparable materials with low cost and good ease of separation is required. Herein magnetic microspheres (i.e., Fe 3 O 4 /Cu) were synthesized through a green single-step solvothermal method for the first time with ethylene glycol serving as reductant and reaction media. The prepared materials were characterized by means of powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectrometry, a vibrating sample magnetometer, and so forth. Additionally, by employing the reduction of 4-nitrophenol to 4-aminophenol as a model reaction, the effects of preparation time and the initial dosage of Cu(NO 3 ) 2 on the rate constant of the catalytic reduction reaction were systematically investigated. Moreover, the obtained hybrid nanocatalysts were also applied to reduce and degrade common organic dyes (rhodamine B and methylene blue) in the presence of NaBH 4 . Quite significantly, it was shown that it could catalytically degrade different organic dyes with excellent catalytic performance and high stability in recycled reactions up to five times. More interestingly, the material can be easily separated from the catalytic system for further use.