Tan Huaqiao, Zhao Zhao, Zhu Wan-Bin, Coker Eric N, Li Binsong, Zheng Min, Yu Weixing, Fan Hongyou, Sun Zaicheng
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.
ACS Appl Mater Interfaces. 2014 Nov 12;6(21):19184-90. doi: 10.1021/am5051907. Epub 2014 Oct 27.
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.
通过硼氢化钠（NaBH₄）与钛酸锶（SrTiO₃）纳米晶体的可控固态反应，开发了一种简便通用的方法在钙钛矿型SrTiO₃（STO）纳米晶体上制备氧空位。合成了具有可调颜色、纳米晶体表面氧空位浓度的STO样品。透射电子显微镜（TEM）结果表明，这些STO样品具有晶体核/非晶壳结构（SrTiO₃@SrTiO₃-x）。X射线光电子能谱（XPS）和电子顺磁共振（EPR）结果表明，氧空位浓度随反应时间和温度的增加而增加。根据热重分析（TGA）数据计算，本研究中氧空位浓度可达5.07%（原子）。紫外可见光谱和光催化结果表明，STO表面的氧空位在影响光吸收和光催化性能方面起着重要作用。然而，过量的氧空位会导致光催化性能下降。在紫外可见光照下，产氢的最佳光催化活性高达2.2 mmol h⁻¹ g⁻¹，约为原始SrTiO₃的2.3倍，对应氧空位浓度为3.28%（原子）。
