Photocatalytic Degradation of Methyl Orange and Metoprolol by Novel Ternary Photocatalyst TiO2-ZnO/g-C3N4 under UV and Visible Light

Novel ternary photocatalyst TiO₂-ZnO/g-C₃N₄ was synthesized via a ball milling-assisted sol-gel method and its photocatalytic performance was tasted in photocatalytic degradation of methyl orange (MO) and metoprolol (MTP) under UV and Visible light. The samples were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), scanning electron microscopy (SEM), and nitrogen physisorption. Optical measurements confirmed that the combination of TiO₂, ZnO, and g-C₃N₄ extended the visible light absorption to 2.63 eV. SEM and FTIR revealed correct coupling between the three semiconductors, and hole density analysis suggested a synergistic effect reducing charge recombination. Additionally, reuse tests demonstrated the chemical stability of the material. In terms of pollutant degradation, the TiO₂-ZnO/g-C₃N₄ composite efficiently removed 97.75% of MO under UV-LED light and 98.57% under visible light in 300 minutes. Similarly, MTP degradation test reached 86.42% and 86.08% under UV-LED and visible light, respectively, after 300 minutes. These results highlight the material's potential for environmental applications, particularly in contaminant removal through photocatalysis.