One-pot synthesized g-C3N4/Fe3O4/CuO magnetic photocatalyst for one-pot synthesis of 2-amino-4H-benzochromenes and methylene blue photodegradation

This article presents the synthesis, characterization, and dual-functional applications of a g-C3N4/Fe3O4/CuO photocatalyst in both environmental remediation and organic synthesis. This study integrated a composite of visible-light-responsive graphitic carbon nitride, narrow-bandgap copper oxide, and magnetically recoverable iron oxide into one synergistic photocatalyst system through a facile solvothermal method. Complete characterizations were made by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM), Energy-Dispersive X-ray Spectroscopy (EDS), Thermogravimetric Analysis/Differential Thermal Analysis (TGA/DTA), Brunauer-Emmett-Teller (BET), Point of Zero Charge (PZC), Vibrating Sample Magnetometry (VSM), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS), and Cyclic Voltammetry (CV). The photocatalyst exhibited the best degradation efficiency for methylene blue, achieving over 90% removal within 60 min under UV light irradiation. At pH = 9, the catalyst exhibited optimum performance, which was explained by enhanced radical generation and surface interactions. CV confirmed efficient electron transfer within the catalyst, hence its suitability for redox reactions. The composite proved very efficient for the one-pot synthesis of 2-amino-4H-benzochromenes, yielding products higher than 89% under neutral and mild conditions. This composite was stable, maintaining over 80% activity after six runs. These results bring g-C3N4/Fe3O4/CuO photocatalysts into the spotlight as efficient, robust, and green material applications in wastewater treatment and green organic synthesis. The high catalytic efficiency, structural robustness, and magnetic recoverability make these candidates potentially active for industrial and environmental applications.