Photocatalytic Properties and 121Sb Mössbauer Spectra of Antimonic Acid Fine Nanoparticles Prepared by Soft Chemical Solution Process

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• 作者：Junhu Wang ; Kiyoshi Ozawa ; Masashi Takahashi ; Masuo Takeda ; and Toru Nonami
• 刊名：Chemistry of Materials
• 出版年：2006
• 出版时间：May 2, 2006
• 年：2006
• 卷：18
• 期：9
• 页码：2261 - 2264
• 全文大小：58K
• 年卷期：v.18,no.9(May 2, 2006)
• ISSN：1520-5002

文摘

Two kinds of dispersed nanoparticle photocatalysts of antimonic acid, HSbO₃·nH₂O, namely, SbI andSbII, were prepared separately by the direct reactions of an aqueous H₂O₂ solution with Sb alkoxidecomplex, Sb(O-i-C₃H₇)₃ and metallic Sb powder according to a soft chemical solution process. Theirphotocatalytic properties were evaluated from methylene blue (MB, C₁₆H₁₈N₃SCl) degradation. SbI showedvery strong adsorption capability and high photocatalytic activity under UV light irradiation. The averagerates of MB degradation were estimated to be 2.403 × 10^-5 m mol h^-1 for SbI and 4.01 × 10^-6 m molh^-1 for SbII. To investigate the reason for their difference in photocatalytic MB degradation, the twoSb-based photocatalysts were characterized by ¹²¹Sb Mössbauer spectroscopy in connection with powderX-ray diffraction and photoabsorption property measurement. The lattice parameters, particle sizes, andrelative surface areas were estimated to be 10.372(3) Å, 35 nm, and 43.5 m² g^-1 for SbI and 10.362(4)Å, 70 nm, and 31.4 m² g^-1 for SbII, respectively. Valuable information was obtained on valence stateand coordination structure of Sb contained in them. These results revealed that SbI had the advantagesof high dispersion, fine crystallinity, and large relative surface area as well as only containing theoctahedrally coordinated Sb⁵⁺ species with d¹⁰ electronic configuration, resulting in having the highphotocatalytic activity for MB degradation under UV light irradiation. A small amount of Sb³⁺ specieswith d⁸ electronic configuration should be considered to be the main reason the photocatalytic performanceof SbII for MB degradation was definitely lower than that of SbI.