Growth, structural and photophysical properties of Bi2GaTaO7

• Published in: Journal of crystal growth Vol. 273; no. 1-2; pp. 241 - 247
• Main Authors: Luan, Jingfei, Zou, Zhigang, Lu, Minghui, Zheng, Shourong, Chen, Yanfeng
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 17.12.2004
• Subjects: Chemistry; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; General and physical chemistry; Inorganic compounds; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Water, oxides, hydroxides, peroxides; Pyrochlore; Cubic lattices; Inorganic compounds; A2. Single crystal growth; Polycrystals; XRD; Defects; Degradation; Unit cell; Reflection spectrum; B1. Oxides; Absorption spectra; Quaternary compounds; Scanning electron microscopy; Light irradiation; Physical radiation effects; Photocatalysis; Transition element compounds; Tantalum oxides; Bismuth oxides; B2. Semiconducting materials; Experimental study; B2. Magneto-optic materials; 61.10.Nz; 82.50.Fv A1. Crystal structure; 74.25.Gz; Gallium oxides; Ultraviolet radiation; Morphology; B2. Semiconducting gallium compounds; 72.80.Jc
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2004.08.127

The new Bi2GaTaO7 compound was synthesized by solid-state reaction method and characterized by powder X-ray diffraction and the Rietveld structure refinement. The Bi2GaTaO7 compound crystallizes in the pyrochlore-type structure, cubic system with space group Fd3m and the lattice parameter a = 10.4516(5)A. The band gap of the Bi2GaTaO7 compound was estimated to be about 2.187 eV. The Bi2GaTaO7 compound shows strong optical absorption in the visible light region (lambda > 420 nm). This indicates that the Bi2GaTaO7 compound has the ability to respond to the wavelength of the visible light region and has potential for splitting water into H2 and O2 under visible light irradiation. Photocatalytic degradation of methylene blue (MB) dye on the Bi2GaTaO7 compound was first investigated under ultraviolet light irradiation. MB was degraded largely after ultraviolet light irradiation for 70 min over the photocatalyst at room temperature in air. The high activity has potential to be kept in a wide range of wavelength up to 568 nm.