Highly thermal stable and highly crystalline anatase TiO2 for photocatalysis.
In the absence of any doping and modification, the anatase-to-rutile phase transformation was inhibited at high temperatures giving rise to highly thermal stable and highly crystalline anatase TiO2 fibers. The initial formation of the TiO2(B) phase is found to be key in inhibiting this transformation. The intermediate structure of the TiO2 fiber comprises an inner anatase core with an outer TiO2(B) shell, which has a specific crystallographic orientation with respect to the anatase structure. During the calcination process from 300 to 800 degrees C, both the TiO2(B) shell and the bulk anatase crystal structure was preserved. At temperatures of 800-900 degrees C the TiO2(B)-to-anatase transformation was finished and a near-pure and thermally stable anatase fiber was obtained. This final product shows the same activity as a standard commercial photocatalyst Degussa P-25 when measured against unit mass, and 5 times the activity when measured with respect to the unit surface area. The anatase TiO2 fibers presented here have considerable interest as practical photocatalysts for water purification, as they can be easily recycled without a decrease in their photocatalytic activity and can be prepared at large scale and at low cost.
Li
Wei
W
State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009, China.
Bai
Yang
Y
Liu
Chang
C
Yang
Zhuhong
Z
Feng
Xin
X
Lu
Xiaohua
X
van der Laak
Nicole K
NK
Chan
Kwong-Yu
KY
D002384:Catalysis; D003460:Crystallization; D006358:Hot Temperature; D010777:Photochemistry / Q000379:methods*; D017319:Photosensitizing Agents / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014961:X-Ray Diffraction
D017319:Photosensitizing Agents; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium