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Ultrasonic Preparation of Hierarchical Graphene‐Oxide/TiO 2 Composite Microspheres for Efficient Photocatalytic Hydrogen Production
Author(s) -
Gao Peng,
Sun Darren Delai
Publication year - 2013
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.201300565
Subject(s) - materials science , photocatalysis , graphene , composite number , hydrogen production , sonication , oxide , chemical engineering , photocurrent , composite material , nanotechnology , microscale chemistry , hydrogen , catalysis , chemistry , metallurgy , optoelectronics , organic chemistry , mathematics education , mathematics , engineering
Hierarchical graphene oxide (GO)‐TiO 2 composite microspheres with different GO/TiO 2 mass ratios were successfully prepared by mixing GO and TiO 2 microspheres under ultrasonic conditions. Ultrasonication helped the GO and TiO 2 microsphere to uniformly mix on the microscale. The results showed that the GO‐TiO 2 composites that were prepared by ultrasonic mixing exhibited significantly higher hydrogen‐evolution rates than those that were synthesized by simple mechanical grinding, owing to synergetic effects, including enhanced light absorption and scattering, as well as improved interfacial charge transfer because of the excellent contact between the GO sheets and TiO 2 microspheres. In addition, GO‐TiO 2 ‐3 (3 wt. % GO) showed the highest hydrogen‐generation rate (305.6 μmol h − ), which was about 13 and 3.3‐times higher than those of TiO 2 microsphere and GO‐P25 (with 3 wt. % GO), respectively. Finally, a tentative mechanism for hydrogen production is proposed and supported by photoluminescence and transient photocurrent measurements. This work highlights the potential applications of GO‐TiO 2 composite microspheres in the field of clean‐energy production.