Zheng Jing, Liu Yousong, Ji Guangbin, Zhang Peng, Cao Xingzhong, Wang Baoyi, Zhang Chuhong, Zhou Xuguang, Zhu Yan, Shi Daning
College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics , Nanjing 210016, P. R. China.
Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy Physics, Chinese Academy of Sciences , Beijing 100049, P. R. China.
ACS Appl Mater Interfaces. 2015 Oct 28;7(42):23431-8. doi: 10.1021/acsami.5b07000. Epub 2015 Oct 16.
Blue oxygen-deficient nanoparticles of anatase TiO2 (H-TiO2) are synthesized using a modified hydrogenation process. Scanning electron microscope and transmission electron microscope images clearly demonstrate the evident change of the TiO2 morphology, from 60 nm rectangular nanosheets to much smaller round or oval nanoparticles of ∼17 nm, after this hydrogenation treatment. Importantly, electron paramagnetic resonance and positronium annihilation lifetime spectroscopy confirm that plentiful oxygen vacancies accompanied by Ti(3+) are created in the hydrogenated samples with a controllable concentration by altering hydrogenation temperature. Experiments and theory calculations demonstrate that the well-balanced Li(+)/e(-) transportation from a synergetic effect between Ti(3+)/oxygen vacancy and reduced size promises the optimal H-TiO2 sample a high specific capacity, as well as greatly enhanced cycling stability and rate performance in comparison with the other TiO2.
采用改进的氢化工艺合成了蓝色缺氧的锐钛矿型二氧化钛纳米颗粒（H-TiO2）。扫描电子显微镜和透射电子显微镜图像清楚地表明，经过这种氢化处理后，TiO2的形态发生了明显变化，从60nm的矩形纳米片变成了小得多的约17nm的圆形或椭圆形纳米颗粒。重要的是，电子顺磁共振和正电子湮没寿命谱证实，通过改变氢化温度，在氢化样品中产生了大量伴随Ti(3+)的氧空位，且浓度可控。实验和理论计算表明，Ti(3+)/氧空位与减小尺寸之间的协同效应实现了良好平衡的Li(+)/e(-)传输，使得最佳的H-TiO2样品具有高比容量，与其他TiO2相比，其循环稳定性和倍率性能也大大增强。
