Pressure-induced phase transitions of exposed curved surface nano-TiO{sub 2} with high photocatalytic activity

Journal Article · Tue Jun 07 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4953218· OSTI ID:22596776

Huang, Yanwei ^[1]; Chen, Fengjiao; Li, Xin; Yuan, Ye; Samanta, Sudeshna; Yu, Zhenhai; Rahman, Saqib; Wang, Lin ^[1]; Dong, Haini ^[1]; Zhang, Jun ^[2]; Yang, Ke; Yan, Shuai ^[3]

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1. Center for High Pressure Science and Technology Advanced Research, Shanghai 201203 (China)
2. College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China)
3. Shanghai Synchrotron Radiation Facility (SSRF), Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201800 (China)

We report a unique phase transition in compressed exposed curved surface nano-TiO{sub 2} with high photocatalytic activity using in situ synchrotron X-ray diffraction and Raman Spectroscopy. High-pressure studies indicate that the anatase phase starts to transform into baddeleyite phase upon compression at 19.4 GPa, and completely transforms into the baddeleyite phase above 24.6 GPa. Upon decompression, the baddeleyite phase was maintained until the pressure was released to 6.4 GPa and then transformed into the α-PbO{sub 2} phase at 2.7 GPa. Together with the results of high-resolution transmission electron microscopy and the pressure-volume relationship, this phase transition's characteristics during the compression-decompression cycle demonstrate that the truncated biconic morphology possessed excellent stability. This study may provide an insight to the mechanisms of stability for high photocatalytic activity of nano-TiO{sub 2}.

• OSTI ID: 22596776
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 21; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BADDELEYITE
COMPRESSION
LEAD OXIDES
MORPHOLOGY
PHASE TRANSFORMATIONS
PHOTOCATALYSIS
PRESSURE RANGE GIGA PA
PRESSURE RANGE MEGA PA 10-100
RAMAN SPECTROSCOPY
SURFACES
SYNCHROTRONS
TITANIUM OXIDES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION