Synthesis and characterization of ZnGa₂O₄ composites and its photocatalytic properties for energy applications

ZnGa₂O₄ nanocomposites have been widely used for photocatalytic degradation of industrial dyes. In this work, ZnGa₂O₄ was synthesized from zinc sulphate heptahydrate ZnSO₄^.10H₂O and Gallium (III) oxide (Ga₂O₃) by hydrothermal method. As prepared, ZnGa₂O₄ nanocomposites was used as a photocatalyst degradation of three organic dyes rhodamine-B, methylene blue, and methyl orange, under ultraviolet (UV) light irradiation. The ZnGa₂O₄ nanocomposites structure, morphology, size and optical properties were studied by X-ray diffraction (XRD), Fourier transform Raman spectroscopy (FT-Raman), scanning electron microscopy (SEM), Transmission electron microscopes (TEM) and photoluminescence spectra (PL). Moreover, the results explained the rate-controlling mechanisms of the dye degradation process followed by second-order kinetics. After 100 min of adsorption kinetic models, the decomposition of rhodamine-B (7.2 Ct mg/L, 5.2 Ct mg/L, and 4.1 Ct mg/L), methylene blue (42.8 qt mg/g, 44.8 qt mg/g, and 45.9 qt mg/g), and methyl orange (42.8 qe mg/g, 44.8 qe mg/g, and 45.9 qe mg/g) respectively. This investigation study offers a promising method to design more efficient ZnGa₂O₄ nanocomposites based photocatalytic degradation of industrial organic dyes.