Direct vapor transport synthesis of ZnGa2O4 nanowires with superior photocatalytic activity

• Published in: Journal of alloys and compounds Vol. 555; pp. 325 - 329
• Main Authors: Tien, Li-Chia, Tseng, Chih-Cheng, Chen, Yu-Lin, Ho, Ching-Hwa
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 05.04.2013; Elsevier
• Subjects: Alloys; Catalysis; Catalytic reactions; Chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Diffraction; Exact sciences and technology; General and physical chemistry; Illumination; Nanocrystals and nanoparticles; Nanostructured materials; Nanowires; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Optical spectroscopy; Oxides materials; Photocatalysis; Photoluminescence; Physics; Scanning electron microscopy; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Ultraviolet; Vapor deposition; Vapor deposition; Optical spectroscopy; Oxides materials; Catalysis; Nanostructured materials; Optical properties; Vacancies; Gallium Zinc Oxides Mixed; Photocatalysis; Photoluminescence; Electron hole pair; Crystal growth from vapors; Methylene blue; Ultraviolet radiation; Spinels; Charge carrier generation; Illumination; Nanowires; Catalyst activity
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2012.12.029

[Display omitted] ► ZnGa2O4 nanowires were synthesized by a direct vapor transport method. ► Intense green and UV emission observed at room temperature. ► Enhanced light absorption contribute to high photocatalytic activity. ZnGa2O4 nanowires have been synthesized by a direct vapor transport process on c-sapphire substrate without any template under low temperature. Their structural and optical properties were characterized by field-emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS) X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), and photoluminescence (PL). Structural characterization revealed that the as-synthesized samples consist of cubic spinel ZnGa2O4 nanowires with 30–90nm in diameter and 3–5μm long. Room temperature photoluminescence show intense ultraviolet (375nm) and green (530nm) emissions originate from oxygen vacancies. Specifically, a near-band-edge emission centered at 283nm was observed. The photocatalytic activity of ZnGa2O4 nanowires was evaluated by the degradation of methyl blue (MB) under ultraviolet light illumination. The results show that ZnGa2O4 nanowires exhibit high photocatalytic activity and is attributed to the enhanced light absorption and strong redox ability of photo-generated electron–hole pairs.