No abstract

Sheet-like Bi 2 O 2 CO 3 /ZnFe 2 O 4 magnetic nanocomposites (denoted as BOC-ZFO) with different amounts of magnetic ZnFe 2 O 4 (ZFO) nanoparticles were successfully produced by a simple hydrothermal route. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDX), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), vibrating sample magnetometer (VSM), and N 2 adsorption-desorption examination were utilized to analyze the structure, morphology, size, phase composition, optical and magnetic properties of the synthesized nanocomposites. The results demonstrated the successful deposition of uniform ZFO nanoparticles onto the surface of sheetlike BOC nanostructures. Then, the catalytic activity of magnetic BOC/ZFO nanocamposites was investigated for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by using sodium borohydride (NaBH 4 ) in hydrous solution and at room temperature. The results showed that BOC/ZFO nanocamposite with 30%wt of ZFO showed the best performance in the reduction of 4-NP with 100% conversion into the amino derivative during 30 min. The effect of catalyst dosage was also investigated on the efficiency of reduction process. Under similar conditions, 2-nitrophenol (2-NP), 4-nitroaniline (4-NA) and 2-nitroaniline (2-NA) were also reduced to the amino derivatives within 16-29 min. The magnetic BOC/ZFO catalyst could be easily separated from the reaction system by an external magnet.

Novel magnetically separable Bi2O2CO3/CoFe2O4 nanocomposites were fabricated by a feasible hydrothermal route. Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), vibrating sample magnetometer (VSM), and N2 adsorption-desorption analysis were employed to examine the structure, morphology, particle size, phase composition, optical and magnetic properties of the as-synthesized nanocomposites. The results of the findings showed demonstrated the successful coupling of spherical CoFe2O4 nanoparticles and plate-like Bi2O2CO3 nanostructures. The catalytic performance of magnetic Bi2O2CO3/CoFe2O4 nanocamposites was evaluated in the reduction of some aromatic nitrocompounds such as nitrophenols and nitroanilines by using sodium borohydride (NaBH4) aqueous solution at room temperature. The Bi2O2CO3/CoFe2O4 nanocamposite with 30 %wt. CoFe2O4 exhibited the best performance in the reduction of aromatic nitrocompounds with 100% conversion into the corresponding amino compounds within 15-30 min with rate constant of 0.10-0.24 min-1. The effect of catalyst dosage was also investigated on the efficiency of reduction process. Furthermore, magnetic Bi2O2CO3/CoFe2O4 nanocomposite could be easily removed by an external magnet from the reaction system.