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Low Temperature Synthesis of High Energy Facets Exposed Sheet–like Anatase TiO 2 Mesocrystals Show Reduced e − /h + Pair Recombination Rates and Enhanced Photoactivity
Author(s) -
Sumi. B.,
Kumar S. Nishanth,
Achu R.,
Kumar B. S. Dileep,
Ray Alok K,
Warrier K. G. K.,
Pillai Saju
Publication year - 2016
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201601412
Subject(s) - anatase , photocatalysis , materials science , photocurrent , photoluminescence , charge carrier , nanotechnology , irradiation , chemical engineering , nuclear chemistry , chemistry , optoelectronics , catalysis , organic chemistry , engineering , physics , nuclear physics
Herein, we report low temperature synthesis of anatase TiO 2 mesocrystals with {001} facets exposed sheet‐like morphology via fluorine‐free synthesis by the synergistic effect of microwave and ultrasound treatments. The synthesized TiO 2 powder showed higher surface area and enhanced photocatalytic degradation of a model dye under white light irradiation. The sheet‐like anatase TiO 2 mesocrystals resulted long‐lived charge carriers and separation that was confirmed from photoluminescence and photocurrent measurements. A five‐fold enhancement in the photocurrent was obtained for the mesocrystals compared to reference sample, which revealed that the orientation of nanocrystallites in sheet‐like morphology play a pivotal role in electron transport. The effect of charge carriers on photocatalytic activity was studied in detail and it followed the order, hydroxyl radicals> holes>electrons. Additionally, the TiO 2 sol showed excellent stability. Further, the photoinactivation of Escherichia coli and Candida albicans was evaluated using zone of inhibition test under indoor irradiation and synthesized anatase TiO 2 showed a clear zone of inhibition with diameter 37.2 mm and 40.0 mm, respectively whereas commercial TiO 2 shows meager inactivation. The results indicate that our approach of combined microwave and sonication can serve as a facile approach for the synthesis of {001} facets exposed anatase sheet‐like TiO 2 mesocrystals under halide‐free and low temperature conditions.