Efficient photocatalytic degradation of methyl green dye on ZnFe₂O₄/reduced graphene oxide nanocomposite

In this study, ZnFe₂O₄ (ZFO) and ZnFe₂O₄/reduced graphene oxide (ZFO/RGO) nanocomposite were successfully synthesized via a one-step hydrothermal method and employed for the photocatalytic degradation of methyl green dye under solar irradiation. Structural and morphological characterizations were carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and UV-Vis diffuse reflectance spectroscopy (UV-DRS), which confirmed the successful formation of the ZFO/RGO hybrid material with enhanced optical properties. The band gaps of ZFO and ZFO/RGO were determined to be 1.9 eV and 1.6 eV, respectively, indicating improved visible-light absorption due to RGO incorporation. Photocatalytic performance evaluation revealed that the ZFO/RGO hybrid material exhibited significantly higher degradation efficiency (88%) within 120 min compared to pristine ZFO (49%). The enhanced activity was attributed to the improved charge separation and suppressed electron-hole recombination facilitated by RGO. Kinetic analysis confirmed that the degradation followed a pseudo-first-order kinetics, with the rate constant (k) for ZFO/RGO calculated as 0.018 min −1 , which is significantly higher than that of ZFO (0.005 min −1 ). Radical scavenger studies indicated that hydroxyl radicals (OH ⋅ ) and superoxide radicals (O 2 ⋅− ) were the primary reactive species responsible for the degradation process. The superior photocatalytic activity of ZFO/RGO nanocomposite can be used as an efficient visible-light-driven photocatalyst for wastewater treatment, and environmental remediation for clean water. • ZnFe₂O₄/reduced graphene oxide (RGO) nanocomposite was successfully synthesized. • Characterizations were carried out using XRD, SEM, EDX, and UV-DRS. • ZFO/RGO hybrid material exhibited higher degradation efficiency (88%). • The degradation followed a pseudo-first-order kinetics, with (k) as 0.018 min −1 . • Radical scavenger studies indicated that (OH ⋅ ) and (O 2 ⋅− ) were primary reactive species.