1. Interfacial Engineering of Nanoporous Architectures in Ga2O3 Film toward Self-Aligned Tubular Nanostructure with an Enhanced Photocatalytic Activity on Water Splitting
- Author
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Yong-Young Noh, Hoa Thi Bui, Taegweon Lee, and Nabeen K. Shrestha
- Subjects
Nanostructure ,Materials science ,Anodizing ,Nanoporous ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,Surfaces and Interfaces ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Isotropic etching ,0104 chemical sciences ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Electrochemistry ,Water splitting ,General Materials Science ,Gallium ,0210 nano-technology ,Spectroscopy - Abstract
The present work demonstrates the formation of self-aligned nanoporous architecture of gallium oxide by anodization of gallium metal film controlled at −15 °C in aqueous electrolyte consisting of phosphoric acid. SEM examination of the anodized film reveals that by adding ethylene glycol to the electrolyte and optimizing the ratio of phosphoric acid and water, chemical etching at the oxide/electrolyte interfaces can be controlled, leading to the formation of aligned nanotubular oxide structures with closed bottom. XPS analysis confirms the chemical composition of the oxide film as Ga2O3. Further, XRD and SAED examination reveals that the as-synthesized nanotubular structure is amorphous, and can be crystallized to β-Ga2O3 phase by annealing the film at 600 °C. The nanotubular structured film, when used as photoanode for photoelectrochemical splitting of water, achieved a higher photocurrent of about two folds than that of the nanoporous film, demonstrating the rewarding effect of the nanotubular structure...
- Published
- 2018