This study reports a novel and efficient method for the synthesis of magnetic copper complex conjugated to calcium lignosulfonate modified with diethylenetriamine (Fe3O4@lignosulfonate@diethylenetetramine@Cu complex (FLD-Cu complex)) as an effective photocatalyst. The structure, morphology, and composition of the synthesized complex were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDS), elemental mapping, vibrating sample magnetometry (VSM), thermogravimetry/derivative thermogravimetry (TG/DTG), and Brunauer–EmmettTeller (BET) analyses. In addition, the photocatalytic performance of FLD-Cu complex in the degradation of organic dyes such as methylene blue (MB) and methyl orange (MO) under UV light was studied. The effects of various parameters such as contact time, photocatalyst dosage, pH, and initial dye concentration on the photocatalyst efficiency were also evaluated. Furthermore, FLD-Cu complex showed high stability and reusability after five successive cycles with no significant loss of photocatalytic activity. This photocatalyst could be isolated readily from the reaction mixture using a permanent magnet.
