Enhanced Photocatalytic Degradation of 2-Butanone Using Hybrid Nanostructures of Gallium Oxide and Reduced Graphene Oxide Under Ultraviolet-C Irradiation

Abstract

Hybrid nanostructures made of gallium oxide (Ga2O3) and reduced graphene oxide (rGO) are synthesized using a facile hydrothermal process method, where the Ga2O3 nanostructures are well dispersed on the rGO surface. The formed Ga2O3-rGO hybrids are characterized via Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), a diffuse reflectance Ultraviolet-visible-near infrared (UV-Vis-NIR) spectrophotometer, Brunauer–Emmett–Teller (BET), and photoluminescence (PL). Gas chromatography mass spectrometry (GC-MS) was used for analyzing volatile organic compounds (VOCs). The photocatalytic activity of the hybrid nanostructures is evaluated via the degradation of the 2-butanone, representing the VOCs under 254-nm radiation in the atmosphere. That activity is then compared to that of the Ga2O3 and commercial TiO2-P25. The Ga2O3-rGO hybrid shows enhanced photocatalytic degradation of 2-butanone compared to Ga2O3 and TiO2-P25, which is attributed to the enhanced specific surface area. The results indicate that the Ga2O3-rGO hybrid could be a promising method of enhancing photocatalytic activity and thereby effectively degrading VOCs, including the 2-butanone.

Hydrothermal Synthesis and Photocatalytic Property of Sn-doped β-Ga2O3 Nanostructure

“…Synthesis of Sn-doped β-Ga 2 O 3 nanostructures.-The detailed experimental procedure used to form the β-Ga 2 O 3 nanostructures via the hydrothermal process, as well as the method of photocatalytic evaluation, have been described in previous reports. 9,17 First, 0.1-M gallium (III) nitrate hydrate (Ga(NO 3 ) 3 •xH 2 O) was dissolved in 50 ml of deionized (DI) water under magnetic stirring at room temperature. The pH of the clear solution was 2.5, and this eventually resulted in the formation of intrinsic β-Ga 2 O 3 nanostructures through the hydrothermal reaction.…”

“…[4][5][6][7] The photocatalytic properties of β-Ga 2 O 3 under UVC have been investigated for environmental applications such as the removal of volatile organic compounds (VOCs). 8,9 Several studies have claimed that the photocatalytic properties of β-Ga 2 O 3 outperformed those of conventional TiO 2 under UVC light 8,9 due to the higher redox ability of photo-generated electron and hole pairs (EHPs); the bandgap energy of Ga 2 O 3 (∼4.9 eV) is higher than that of TiO 2 (∼3.3 eV). 10 In general, photocatalytic efficiency increases with the surface area of photocatalysts because the photocatalytic reaction occurs on the catalyst's surface.…”

Impact of Al doping on a hydrothermally synthesized β-Ga2O3 nanostructure for photocatalysis applications

“… 5 β-Ga 2 O 3 is also considered an effective photocatalyst under ultraviolet-C (UVC) light irradiation for the generation of hydrogen 6–8 and removal of volatile organic compounds (VOCs). 9–12 β-Ga 2 O 3 has a high redox potential, which is beneficial for photocatalytic reactions under photoexcitation conditions. 9,13 Its redox potential is higher than TiO 2 , so it exhibits better photocatalytic performance than conventional TiO 2 photocatalysts.…”

Comparison of Ga2O3 and TiO2 Nanostructures for Photocatalytic Degradation of Volatile Organic Compounds

“…Photocatalytic oxidation (PCO) is a promising method to remove low-level VOCs compared with absorption and incineration methods because it is effective, inexpensive, and eco-friendly [2]. Semiconductor nano/microstructures can be used as efficient photocatalytic platforms wherein charge carriers (electron and hole pairs) are generated upon light irradiation with above-bandgap excitation [3,4]. These photo-generated electron-hole pairs within semiconductor photocatalysts can generate reactive oxygen species (ROSs such as hydroxyl (OH -• ) and superoxide (O 2 -• ) radicals) that turn the adsorbed VOCs into CO 2 and H 2 O.…”