Microwave hydrothermal synthesis of MSnO3 (M2+ = Ca2+, Sr2+, Ba2+): effect of M2+ on crystal structure and photocatalytic properties
- 840 Downloads
A series of alkaline earth metal stannates, MSnO3 (M2+ = Ca2+, Sr2+, Ba2+), has been synthesized by a microwave hydrothermal method and subsequent heat treatment process for the first time. The obtained samples are characterized by X-ray diffraction, Brunauer–Emmett–Teller (BET) surface area analysis, UV–Vis diffuse reflectance spectroscopy, scanning electron microscopy, and a photoluminescence technique with terephthalic acid. It is found that the variation of M2+ radius in MSnO3 leads to a change in the crystal structure and the photocatalytic degradation activity for methyl orange. With the increase of M2+ radius, dipole moments are generated in octahedral units because of the octahedral tilting distortion, which may facilitate the mobility of charge carriers and improve the activities of MSnO3. The wider band gap and larger BET surface area caused by the decrease of M2+ radius also contribute to photocatalytic performances. In addition, compared with the conventional hydrothermal method, higher activity is achieved on the samples prepared by means of the microwave method. Our findings may provide insights in fabrication of highly efficient photocatalysts by adjusting the counter-cation radius.
KeywordsPhotocatalytic Activity Methyl Orange SrMoO4 PbMoO4 TiO6 Octahedra
This work was supported by the National Natural Science Foundation of China (21003022, 21177024, 21273036, and 21303019) and the Natural Science Foundation of Fujian Province (2011J01041).
- 28.Sutton WH (1989) Microwave processing of ceramic materials. Am Ceram Soc Bull 68:376–386Google Scholar
- 47.Kohno M, Ogura S, Sato K, Inoue Y (1997) Reduction and oxidation of BaTi4O9 with a pentagonal prism tunnel structure effects on radical formation upon UV irradiation and on the activity of RuO2/BaTi4O9 photocatalyst for water decomposition. J Chem Soc Faraday Trans 93:2433–2437CrossRefGoogle Scholar
- 48.Xu Y, Schoonen MAA (2000) The absolute energy positions of conduction and valence bands of selected semiconducting minerals. Am Mineral 85:543–556Google Scholar