Organic additives assisted synthesis of mesoporous β-Ga2O3 nanostructures for photocatalytic dye degradation

Functional semiconductor beta-Ga2O3 nanostructures with interesting morphologies like blocks, spindles and rods were fabricated using hydrothermal process employing cationic (CTAB), anionic (SDS) and non-ionic (PEG) organic additives. Well-defined and monodispersed uniform mesoporous nanostructures of beta-Ga2O3 were observed using scanning electron microscopy. The diameter of nanostructures was evaluated from transmission electron microscopy images and was found to be similar to 125, 70 and 50 nm, respectively, for nanoblocks, nanospindles and nanorods, which are in accordance with XRD analysis. Structural characterization using XRD and FTIR spectroscopy revealed the single crystalline monoclinic structure of beta-Ga2O3 with high purity. The thermal decomposition process was monitored through a thermogravimetric/differential thermal analyzer. The N-2 adsorption/desorption analysis revealed the distribution of mesopores with high surface area. Furthermore, the photocatalytic activities of semiconductor beta-Ga2O3 nanostructures toward Rhodamine B under ultraviolet light showed enhanced activity over commercial Degussa P25 and bulk Ga2O3, with beta-Ga2O3 nanorods presenting higher photocatalytic ability. The enhanced photocatalytic activity of beta-Ga2O3 nanostructures ascribed to specific surface area, pore size distribution and optical properties have also been addressed.