Influence of Green-Synthesized Fe<sub>3</sub>O<sub>4</sub>/ PEG Nanocomposite Concentration on Photodegradation of Methylene Blue

Research has been conducted on Fe₃O₄/PEG material applied as a photocatalyst. This research is motivated by the many textile industries that pollute the environment with their liquid waste disposal. The purpose of this research is to analyze the effect of concentration variation of Fe₃O₄/PEG nanocomposites that are green synthesized using Moringa oleifera extract on the photodegradation efficiency of Methylene Blue (MB) dye in water. The nanocomposites formed were then characterized through several techniques, including X-Ray Diffraction, Fourier Transform Infrared Spectroscopy, Vibrating Sample Magnetometer, and Ultraviolet-Visible (UV-Vis) spectrophotometry. Afterwards, the nanocomposites were tested in the MB photocatalytic process with various concentration to determine their effect on the degradation efficiency under UV irradiation. The material characterization results show that the nanocomposites has an inverse spinel cubic crystal structure with a crystallite size of 15.93±0.03 nm, and a lattice parameter of 8.17 Å. UV-Vis analysis showed an absorption peak at a wavelength of 322 nm with a direct energy band gap of 3.8 eV, and properties towards superparamagnetic with a saturation magnetization of 49.9 emu/g. Photocatalytic tests showed an increase in efficiency as the catalyst concentration increased, reaching the highest degradation of 68.2% at a mass of 0.09g. Therefore, this nanocomposite has potential as a photocatalyst.