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

Abstract

The photocatalytic degradation of formaldehyde, acetaldehyde, toluene, and styrene are compared using monoclinic Ga(2)O(3)and anatase TiO(2)nanostructures under ultraviolet-C irradiation. These Ga(2)O(3)and TiO(2)photocatalysts are characterized using a field emission scanning electron microscope, a powder X-ray diffraction system, the Brunauer-Emmett-Teller method, and a Fourier transform infrared spectrometer. The Ga(2)O(3)shows a higher reaction rate constant (k, min(-1)) than TiO(2)by a factor of 7.1 for toluene, 8.1 for styrene, 3.1 for formaldehyde, and 2.0 for acetaldehyde. The results demonstrate that the photocatalytic activity ratio of the Ga(2)O(3)over the TiO(2)becomes more prominent toward the aromatic compounds compared with the nonaromatic compounds. Highly energetic photo-generated carriers on the conduction/valence band-edge of the Ga2O3, in comparison with that of the TiO2, result in superior photocatalytic activity, in particular on aromatic volatile organic compounds (VOCs) with a high bond dissociation energy.