Morphology tuned Ga2O3 nanostructures for visible light-assisted dye-sensitized photocatalytic water remediation

Abstract

Low-dimensional Ga2O3 was synthesized via a facile chemical route aiming at easy morphological tuning. Different Gallia precursors as starting materials for hydrothermal synthesis eventually led to spherical nanoparticles and fractured nanobricks as the end product. In addition to the regular characterization of phase, morphology, chemical bond, and surface-related investigations, both samples were subjected to visible-light-induced photocatalytic degradation of toxic organic pollutants. Despite its wide bandgap, the samples showed an efficient dye degradation ability under visible excitation, which was explained as originating due to the sensitization of the dyes. The nitrate-salt-originated nanobricks appeared to be more efficient in degrading rhodamine B (RhB) than the nanospheres fabricated using chloride-salt, presenting degradation rate constants of 0.0394 and 0.0057 min−1, respectively. The performances of the samples differed due to their electronic band positions. Also, morphological features like higher specific surface area, porosity, and aspect ratio enabled faster degradation of RhB for nanobricks. However, as reflected in BET studies, the lower surface area and pore density caused comparatively weaker degradation performance of the nanospheres. This remediation technology can optimize similar future catalyst systems fabricated using the hydrothermal-synthesis route for wastewater treatment.