Green sonochemical process for preparation of polyethylene glycol–Fe 3 O 4 /ZnO magnetic nanocomposite using rambutan peel extract as photocatalyst, for removal of methylene blue in solution

The main objective of this study is the preparation of a polyethylene glycol (PEG)–Fe3O4/ZnO magnetic nanocomposite using a green sonochemical synthesis method with rambutan peel extract as a stabilizing agent for photocatalytic methylene blue (MB) degradation. The synthesized nanocomposites were characterized using field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction and UV–visible methods. The field emission scanning electron microscopy results showed the size of nanocomposite was 20–30 nm and had the bandgap energy of 2.58 eV. The effects of the photocatalyst and process time were investigated. The kinetics were investigated, and the regeneration of the photocatalyst was evaluated. Kinetic experiments on MB degradation using the nanocomposite showed good agreement with the Langmuir–Hinshelwood model, and the photocatalyst could remove over 98% of the MB within 90 min.