Coverage of carbon nanotubes with titania nanoparticles for the preparation of active titania-based photocatalysts

Abstract

TiO2 nanoparticles were deposited on carbon nanotubes (CNTs) to improve their photocatalytic activity. The outer surface of the CNTs could be uniformly covered with TiO2 nanoparticles using the hydrolysis of titanium tetraisopropoxide (Ti(OiPr)4) in the presence of urea or glycine amide. The urea and glycine amide acted as linker molecules between the TiO2 nanoparticles and the CNT surfaces. The TiO2-coated CNTs showed a higher catalytic activity for the photodegradation of organic molecules than TiO2 alone. The addition of the CNTs to the TiO2 photocatalytic system retarded the recombination of the electron–hole pairs generated in the photo-irradiated TiO2. When Pt metal particles were inserted in the cavities of the CNTs in the TiO2-coated CNT catalyst system, further improvements in the photocatalytic activity were observed. The TiO2-coated CNTs with Pt metal particles displayed a unique catalytic performance in the photocatalytic degradation of organic impurities in water.