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

Functional semiconductor β-Ga 2 O 3 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 β-Ga 2 O 3 were observed using scanning electron microscopy. The diameter of nanostructures was evaluated from transmission electron microscopy images and was found to be ∼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 β-Ga 2 O 3 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 β-Ga 2 O 3 nanostructures toward Rhodamine B under ultraviolet light showed enhanced activity over commercial Degussa P25 and bulk Ga 2 O 3 , with β-Ga 2 O 3 nanorods presenting higher photocatalytic ability. The enhanced photocatalytic activity of β-Ga 2 O 3 nanostructures ascribed to specific surface area, pore size distribution and optical properties have also been addressed.