Enhanced Visible-Light Photodegradation of Methylene Blue and Amoxicillin by Sulfur-Doped g-C3N4 Coupled with MnFe2O4

In this present work, a visible-light-active sulfur-doped graphitic carbon nitride (S-g-C ₃ N ₄ ) coupled with manganese ferrite (MnFe ₂ O ₄ ) nanocomposite was successfully synthesized and investigated for its photocatalytic performance. Structural as well morphological characterizations performed utilized X-ray diffraction (XRD), which confirmed the crystalline phases of both MnFe ₂ O ₄ as well as S-g-C ₃ N ₄ . Scanning electron microscopy (SEM) revealed a well-distributed nanocomposite morphology, while energy-dispersive X-ray spectroscopy (EDX) verified the elemental composition also successful incorporation of Mn, Fe, O, C, and N. The optical band gap of the MnFe ₂ O ₄ /S-g-C ₃ N ₄ composite was determined to be 1.77 eV, enabling efficient visible light absorption. Under 120 minutes of visible light-irradiation, the composite exhibited high photocatalytic degradation efficiencies of 93.26 % for methylene blue (MB) and 89.92 % for amoxicillin (AMX). Scavenger studies revealed that reactive oxygen species played a major role of the degradation pathways. Furthermore, recyclability tests over four successive cycles showed consistent photocatalytic activity, confirming the material’s stability and reusability. The synergistic interaction between S-g-C ₃ N ₄ also MnFe ₂ O ₄ facilitated efficient charge separation and enhanced degradation efficiency, suggesting the potential of this composite as a sustainable photocatalyst for wastewater treatment.