Reductant‐Free and In‐Situ Green Synthesis of Ag Nanoparticles on Fe3O4@Nanocellulose and Their Catalytic Activity for the Reduction of Dyes

Abstract

AbstractIn this work, magnetic nanofibrillated cellulose (Fe3O4@NFC) was prepared and used as green support and reducing agent for the facile synthesis of silver nanoparticles (Ag NPs) by the reflux and hydrothermal methods. The structure of the as‐prepared composites was characterized by various spectroscopic techniques including X‐ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy dispersive spectroscopy, inductively coupled plasma atomic emission spectroscopy, vibrating sample magnetometer, and nitrogen adsorption‐desorption isotherms. The catalytic activity of synthetic nanocomposites by the reflux (Fe3O4@NFC/Ag‐1) and hydrothermal (Fe3O4@NFC/Ag‐2) methods was investigated in the removal of organic dyes. Moreover, the effects of catalyst amounts, pH values, and drying process on the catalytic activity were also evaluated. The results indicated that the Ag loading and specific surface area of freeze‐dried Fe3O4@NFC/Ag‐1 were 1.8 wt % and 37 m2 g−1, respectively. The catalyst showed the saturation magnetization of 23.5 emu g−1 and could be easily separated and reused again. The freeze‐dried Fe3O4@NFC/Ag‐1 (0.02 g) synthesized by the reflux method in neutral conditions (pH=7) showed high catalytic activity for the reduction of 4‐nitrophenol (4‐NP), methyl orange (MO), and methylene blue (MB) with rate constants of 40.7×10−3 s−1, 7.5×10−3 s−1, and 2.9×10−3 s−1, respectively.