Enhancing the photocatalytic activity of Ga2O3-TiO2 nanocomposites using sonication amplitudes for the degradation of Rhodamine B dye

A Ga2O3-TiO2 photocatalyst was synthesized by a mechanomixing method followed by a sonication technique using different amplitudes of sonication (0%, 25%, 50%, and 75% of 20 kHz). The prepared photocatalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier-transform infrared, Brunauer-Emmett-Teller (BET) surface area (S-BET), zeta potential, and optical techniques. Ga2O3-TiO2 exhibited an excellent photocatalytic activity for Rhodamine B (RhB) dye degradation under UV irradiation. The RhB degradation rate rose linearly with the increase of sonication amplitude. The photodegradation rate (k) of the synthesized samples was calculated according to the Langmuir-Hinshelwood kinetic expression. It reached a maximum of 5.25 x 10(-2) min(-1) with R-2 of 0.99 for Ga2O3-TiO2 (75%) photocatalysts. The main reactive species were detected through radical scavenging experiments. The formation of hole reactive species is the rate-determining step in the case of Ga2O3-TiO2 (75%) photocatalysts.