Facile and green fabrication of copper‐based magnetically recoverable yolk–shell nanocatalysts with high catalytic performance for nitroaromatic reduction

Abstract

A simple method was reported to achieve a green yolk–shell Fe3O4@SiO2@CuO nanocatalysts (YS‐Fe3O4@SiO2@CuO). Glucose (G) and lactose (L), as a grafting agent, were applied for decorating CuO on the magnetic nanoparticles surface and then using calcination method, yolk–shell structure was obtained. Characterization of nanocatalysts was carried out using inductively coupled plasma–optical emission spectrometry (ICP‐OES), field emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), energy‐dispersive X‐ray (EDX)‐Mapping, thermogravimetric analysis (TGA), X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), X‐ray photoelectron spectroscopy (XPS), Brunauer, Emmett, and Teller (BET), and vibrating sample magnetometer (VSM) analyses and the results confirmed the successful synthesis of these catalysis. The activity of the nanocatalysts were studied to reduce nitroaromatic compounds monitoring by UV–Vis spectra. In the model reaction, 4‐nitrophenol was reduced using YS‐Fe3O4@SiO2@CuO(G) and YS‐Fe3O4@SiO2@CuO(L), with the activity factors (k′) of 3218 and 2023 s−1 g−1, and rate constants (Kapp) of 0.56 and 1.19 min−1, respectively. The advantages of prepared nanocatalysts were good stability and high conversion. The magnetic property of nanocatalysts makes them easy to recover in multiple cycles.