3-Dimensional cube In₂O₃/g-C₃N₄ nanosheet composite for photodegradation of VOC-contaminated water

In this study, a hydrothermal approach was used to couple three-dimensional In₂O₃ cubes with graphitic carbon nitride (g-C₃N₄) nanosheets to form In₂O₃/g-C₃N₄ composites. To investigate the charge carrier border for photocatalytic enhancement, pure In₂O₃, pure g-C₃N₄ and In₂O₃/g-C₃N₄ composites were prepared. The coupling of In₂O₃ particles to the g-C3N4 nanosheets was examined using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS) and electrochemical impedance spectroscopy (EIS). Well-pure In₂O₃ with a clearly defined cubic crystal plane phase was characterized by the XRD patterns. Elemental mapping and optical properties were assessed using SEM-EDX and UV-DRS analysis. For the degradation of benzene, methyl tert-butyl ether (MTBE) and 1-Butanol, pure In₂O₃, pure g-C₃N₄, and In₂O₃/g-C₃N₄ composites were applied under visible light irradiation. Among all samples, the 20 %In₂O₃/g-C₃N₄ composite exhibited the highest performance for all types of volatile organic compound degradation. A Z-scheme for the combined photocatalytic and degradation processes was proposed.