Enhanced Photocatalytic Activity in β‐Ga₂O₃ Nanobelts

Abstract

b-Ga 2 O 3 nanobelts have been synthesized by a vapor transport process under different ambient oxygen. Their structural and optical properties were characterized by field-emission scanning electron microscopy, X-ray diffraction, photoluminescence (PL), and absorbance measurements. Structural characterization revealed that the as-synthesized samples consist of monoclinic b-Ga 2 O 3 nanobelts with comparable surface area. Samples prepared under high oxygen ambient possessed large numbers of gallium-associated defects confirmed by PL and absorbance measurements. The photocatalytic activity of b-Ga 2 O 3 nanobelts was evaluated by the degradation of organic dyes (rhodamine B and methyl blue) under ultraviolet light illumination. The results demonstrated that b-Ga 2 O 3 nanobelts exhibited superior photocatalytic activity and stability as compared with commercial b-Ga 2 O 3 powder. The photocatalytic activity of b-Ga 2 O 3 nanobelts was greatly enhanced and attributed to the large numbers of acceptor states associated with gallium defects. The origin of enhanced photocatalytic activity of b-Ga 2 O 3 nanobelts was discussed.

Photocatalytic degradation of organic pollutants by shape selective synthesis of β-Ga2O3 microspheres constituted by nanospheres for environmental remediation

“…7f) by using β-Ga 2 O 3 microspheres comprised of nanospheres as the catalyst as also suggested by Li-Chia Ten et.al 42. Therefore, the presence of both 20 illumination and the β-Ga 2 O 3 catalysts were necessary for the efficient degradation of RhB and MB.…”

Synthesis of β-Ga2O3 nanorods by catalyzed chemical vapor deposition and their characterization

“…The emission peak centered at 357 nm by Gaussian fitting is in the UV region, which is an intrinsic transition and attributed to the recombination of the self-trapped excitons [22]. The green and blue emission peaks originate from the recombination of an electron on a donor due to the oxygen vacancies (V O ) and a hole on an acceptor caused by the gallium vacancies (V Ga ) or the gallium-oxygen vacancy pairs (V Ga -V O ) [21,23]. Therefore, the blue emission peak centered at 420 nm by Gaussian fitting is excited with the photon energy slightly below the band gap of b-Ga 2 O 3 , which is generated by the recombination of the donor bands (V O ) close to the valence bands and the acceptor bands consisting of the galliumoxygen vacancy pairs (V Ga -V O ).…”

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

“…If surface defect states exist, it may be able to trap the electron or hole, the recombination is prevented and the rate of oxidation-reduction reactions may be increased. The photocatalytic activity is known to be dependent on the crystallinity, surface area and morphology and it may be improved by slowing the recombination of photogenerated electron-hole pairs, extending the excitation wavelength to lower energy range, and increasing the amount of surface-adsorbed reactant species [3,13,31,32]. Thus the enhanced photocatalytic activates of b-Ga 2 O 3 NWs may be ascribed to the significant surface related defects originating from the high surface to volume ratio [13].…”

“…1D b-Ga 2 O 3 exhibits unusual optical, photocatalytic, electronic and mechanical properties as compared to those of bulk materials, due to the significant surface related defects originating from the high surface to volume ratios. In addition, some important advantages such as good high temperature stability, oxidation resistance and stable electric properties, demonstrate their potential basic building blocks for new classes of environmentally conscious electronics [12,13].…”

“…Recently, b-Ga 2 O 3 crystals have found numerous applications in different fields including DUV photodectors [7], light-emitting diodes (LEDs) [8], conductive windows [9], transparent field-effect transistors (FETs) [10], phosphors [11], gas sensors [12] and photocatalytic degradation of organic pollutants [13]. In recent years, one-dimensional (1D) nanostructure based b-Ga 2 O 3 , such as nanowires and nanobelts, have attracted much attention.…”