Magnetic and visible light-induced novel green synthesized magnetic Co ₃ O ₄ photocatalysts via sunflower seed meal extract for anionic and cationic dye removal by adsorption assisted photocatalytic degradation

This study was aimed at the preparation of m-Co₃O₄ NPs (magnetic Co₃O₄ nanoparticles) from sunflower seed meal (SFSM) which is the waste of sunflower seed oil factories, and their application as a photocatalyst for the adsorption assistant photocatalysis degradation of methylene blue (MB), and direct yellow-50 (DY-50) under the visible irradiations. Also, the photocatalytic performance of m-Co₃O₄ NPs was evaluated in synthetic wastewater. The produced m-Co₃O₄ NPs were ferromagnetic with a saturation magnetization value of 4.3 emu g^-1 and the degradation of cationic MB and anionic DY-50 dyes by 100% and 93% in 20 min and 35 min, respectively, by adsorption-assisted photocatalytic process under visible light was achieved. The reactions were found to be pseudo-second-order equation for the adsorption-assisted photocatalytic process for both dyes. The photocatalytic activity of m-Co₃O₄ NPs decreased slightly even after five repeated cycles. These results show that the m-Co₃O₄ NPs can be used successfully in dye treatment in wastewater with their adsorption-assisted photocatalytic properties, activation by visible light, magnetic separability, and low-cost production.