title: Oxygen vacancy enhanced photocatalytic activity of pervoskite SrTiO(3).
abstract: A facile and general method has been developed to fabricate oxygen vacancies on perovskite SrTiO3 (STO) nanocrystals through a controllable solid-state reaction of NaBH4 and SrTiO3 nanocrystals. STO samples with tunable color, oxygen vacancy concentration on nanocrystal surface have been synthesized. TEM results reveal that these STO samples have a crystalline core/amorphous shell structure (SrTiO3@SrTiO3-x). XPS and EPR results disclose that the oxygen vacancy concentration increases with the increase of reaction time and temperature. The concentration of oxygen vacancies calculated from TGA data, could reach 5.07% (atom) in this study. UV-vis spectra and photocatalytic results indicate that oxygen vacancies on STO surface play an important role in influencing the light absorption and photocatalytic performance. However, an excess amount of oxygen vacancies leads to a decrease of photocatalytic performance. The optimal photocatalytic activity for H2 production under UV-vis irradiation is up to 2.2 mmol h(-1) g(-1), which is about 2.3 times than the original SrTiO3, corresponding to 3.28% (atom) of oxygen vacancy concentration.
authors.affiliation: State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences , 3888 East Nanhu Road, Changchun 130033, P. R. China.
authors.forename: Huaqiao
authors.initials: H
authors.lastname: Tan
authors.forename: Zhao
authors.initials: Z
authors.lastname: Zhao
authors.forename: Wan-Bin
authors.initials: WB
authors.lastname: Zhu
authors.forename: Eric N
authors.initials: EN
authors.lastname: Coker
authors.forename: Binsong
authors.initials: B
authors.lastname: Li
authors.forename: Min
authors.initials: M
authors.lastname: Zheng
authors.forename: Weixing
authors.initials: W
authors.lastname: Yu
authors.forename: Hongyou
authors.initials: H
authors.lastname: Fan
authors.forename: Zaicheng
authors.initials: Z
authors.lastname: Sun
keywords: NaBH4; SrTiO3; core/shell nanostructure; oxygen vacancy; photocatlytic H2 generation