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Microwave‐Hydrothermal Preparation and Visible‐Light Photoactivity of Plasmonic Photocatalyst Ag‐TiO 2 Nanocomposite Hollow Spheres
Author(s) -
Xiang Quanjun,
Yu Jiaguo,
Cheng Bei,
Ong H. C.
Publication year - 2010
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.200900695
Subject(s) - photocatalysis , materials science , rhodamine b , visible spectrum , nanocomposite , x ray photoelectron spectroscopy , raman spectroscopy , scanning electron microscope , surface plasmon resonance , anatase , chemical engineering , titanium dioxide , photochemistry , nanoparticle , nanotechnology , chemistry , composite material , optics , catalysis , optoelectronics , organic chemistry , physics , engineering
Visible‐light‐driven plasmonic photocatalyst Ag‐TiO 2 nanocomposite hollow spheres are prepared by a template‐free chemically‐induced self‐transformation strategy under microwave‐hydrothermal conditions, followed by a photochemical reduction process under xenon lamp irradiation. The prepared samples are characterized by using scanning electron microscopy , transmission electron microscopy , X‐ray diffraction, N 2 adsorption‐desorption isotherms, X‐ray photoelectron spectroscopy, UV/Vis and Raman spectroscopy. Production of ⋅OH radicals on the surface of visible‐light illuminated TiO 2 was detected by using a photoluminescence method with terephthalic acid as the probe molecule. The photocatalytic activity of as‐prepared samples was evaluated by photocatalytic decolorization of Rhodamine B (RhB) aqueous solution at ambient temperature under visible‐light irradiation. The results show that the surface plasmon absorption band of the silver nanoparticles supported on the TiO 2 hollow spheres was red shifted, and a strong surface enhanced Raman scattering effect for the Ag‐TiO 2 nanocomposite sample was observed. The prepared nanocomposite hollow spheres exhibits a highly visible‐light photocatalytic activity for photocatalytic degradation of RhB in water, and their photocatalytic activity is higher than that of pure TiO 2 and commercial Degussa P25 (P25) powders. Especially, the as‐prepared Ag‐TiO 2 nanocomposite hollow spheres at the nominal atomic ratio of silver to titanium ( R ) of 2 showed the highest photocatalytic activity, which exceeds that of P25 by a factor of more than 2.