Synthesis of α-Fe2O3 nanoparticles from soft magnetic FeSiAl alloy cores of spent printed circuit boards and their application in visible-light-driven degradation of methylene blue dye

Abstract

This study aims at 3R recovery, reuse, and recycling of metals from spent printed circuit boards (PCBs). Here, soft magnetic FeSiAl alloy cores of spent PCBs were used to synthesize α-Fe2O3 nanoparticles (NPs) for visible-light-driven degradation of methylene blue (MB) dye. The α-Fe2O3 NPs were synthesized by dissolving FeSiAl in a mixture of mild organic acids such as citric acid and ascorbic acid. The α-Fe2O3 NPs were characterized by powder XRD, TG-DSC, FESEM-EDX, HRTEM, UV–Vis DRS, and BET isotherm. The synthesized α-Fe2O3 NPs were flat spindle shaped and a few were oval with a particle size between 20 and 30 nm. Under visible light irradiation, the α-Fe2O3 NPs showed high efficiency for the degradation of MB dye in the presence of H2O2. To get optimum conditions, various experiments such as catalyst dosage, volume of H2O2, [MB], and nature of light were studied. Thus, it can be proposed that the present study is simple, environmentally benign, and highly efficient for the synthesis of α-Fe2O3 NPs and subsequent degradation of MB dye.