Growth of β-Ga2O3 nanowires and their photocatalytic and optical properties using Pt as a catalyst

Growth of Ga2O3 nanowires (NWs) was carried out by vapor-liquid-solid (VLS) on silicon substrates using Pt as a catalyst. Structural analysis revealed that the Ga2O3 NWs are single phase nature with monoclinic beta-Ga2O3 crystal structure. The optical functions of beta-Ga2O3 NWs films have been determined by ellipsometry investigations from 300-2100 nm. A two layer model employing the Cauchy dispersion model for the main layer and Bruggeman effective medium approximation (BEMA) for the surface layer was found to be sufficient and reasonable. Low refractive index values comparable to those of bulk material, which may ascribed to the low packing density for the films obtained by the used VLS growth method, are obtained. A direct optical band gap value of 3.58 eV was observed. The photocatalytic activity of beta-Ga2O3 NWs was evaluated by the degradation of methylene blue. The beta-Ga2O3 NWs showed enhanced photocatalytic activity. (C) 2012 Elsevier B.V. All rights reserved.