Photodegradation enhancement of organic dyes using magnetically separable and reusable Fe3O4/rGO nanocomposites green-synthesized utilizing plant leaves extract

Abstract

This study aims to investigate the facile fabrication of Fe3O4/rGO nanocomposites based on the green synthesis method, utilizing Moringa oleifera and Amaranthus viridis extracts for photocatalytic degradation application. The coprecipitation and modified Hummer methods were used to synthesize Fe3O4 and rGO, respectively. Both materials were stirred to connect Fe3O4 on the surface of the rGO sheet to produce a nanocomposite. The nanocomposites as a photocatalyst were characterized to investigate the structural, bonding, optical, and magnetic properties. The X-ray diffraction spectrum of Fe3O4/rGO nanocomposites is cubic inverse spinel with a crystalline size around 10 nm. The transmission electron microscope results show a decrease in particle size of Fe3O4/rGO with the addition of rGO. Fe–O functional groups in the nanocomposite show the presence of Fe3O4 on the rGO surface. The addition of rGO concentration affects the saturation magnetization and coercivity values of the nanocomposites. Meanwhile, the methylene blue degradation efficiency is optimal for Fe3O4/rGO nanocomposites at a concentration of 5:5, reaching 99.3 % degradation during a 3-h photocatalytic process. The magnetic potential of Fe3O4/rGO nanocomposites means that the photocatalyst can be recycled up to three times with a high degradation rate. Therefore, the Fe3O4/rGO nanocomposite has the potential as a reusable, environmentally friendly, and cost-effective photocatalyst for the removal of organic pollutants from wastewater.

Keywords

• Green synthesis
• Fe3O4
• rGO
• Nanocomposites
• Methylene blue degradation