Effects of the SrTiO 3 support on visible-light water oxidation with Co 3 O 4 nanoparticles

• Published in: Dalton transactions : an international journal of inorganic chemistry 2017-12, Vol.46 (48), p.16959-16966
• Main Authors: Okazaki, Megumi, Eguchi, Miharu, Uchiyama, Tomoki, Lu, Daling, Kato, Hideki, Uchimoto, Yoshiharu, Kakihana, Masato, Maeda, Kazuhiko
• Format: Article
• Language: English
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/C7DT03444J

The photocatalytic activity of SrTiO modified with Co O nanoparticles for water oxidation under visible light (λ > 480 nm) was investigated with respect to the physicochemical properties of the SrTiO support. SrTiO was synthesized by a polymerized complex method or a hydrothermal method, followed by calcination in air at different temperatures in order to obtain SrTiO particles having different sizes. Co O nanoparticles, which provide both visible light absorption and water oxidation centers, were loaded on the as-prepared SrTiO by an impregnation method using Co(NO ) as the precursor, followed by heating at 423 K in air. Decreasing the SrTiO particle size (that is, improving the crystallinity) enhanced the photocatalytic activity by promoting the formation of Co O nanoparticles that provided optimal light absorption and catalytic sites. However, Co O aggregation occurred on overly large SrTiO particles, leading to a decrease in activity. This study demonstrates the possibility of tuning the photocatalytic activity of a Co O -loaded wide-gap semiconductor for visible light water oxidation through the appropriate selection of the support material.