Open AccessMetastable β‐Bi 2 O 3 Nanoparticles with Potential for Photocatalytic Water Purification Using Visible Light Irradiation
Author(s) -
Schlesinger Maik,
Weber Marcus,
Schulze Steffen,
Hietschold Michael,
Mehring Michael
Publication year - 2013
Publication title -
chemistryopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 29
ISSN - 2191-1363
DOI - 10.1002/open.201300013
Subject(s) - photocatalysis , crystallite , nanoparticle , materials science , rhodamine b , catalysis , annealing (glass) , diffuse reflectance infrared fourier transform , bet theory , nuclear chemistry , bismuth , chemical engineering , photochemistry , chemistry , nanotechnology , organic chemistry , composite material , engineering , metallurgy
Photocatalytic studies under visible light irradiation using nanosized β‐Bi 2 O 3 are reported. β‐Bi 2 O 3 nanoparticles are prepared starting from the well‐defined bismuth oxido cluster [Bi 38 O 45 (OMc) 24 (DMSO) 9 ]⋅2 DMSO⋅7 H 2 O (OMc=O 2 CC 3 H 5 ) using a straightforward hydrolysis and annealing protocol. Powder X‐ray diffraction studies, transmission electron microscopy, diffuse reflectance UV/Vis spectroscopy and nitrogen adsorption measurements (using the Brunauer–Emmett–Teller (BET) theory) are used for the characterization of the as‐prepared β‐Bi 2 O 3 . By time‐dependent annealing, the crystallite size can be controlled between (17±2) nm and (45±5) nm with BET surface areas of 7 to 29 m 2 g −1 . The indirect band gap of the as‐prepared β‐Bi 2 O 3 amounts to (2.15±0.05) eV. The decomposition rates for rhodamine B (RhB) solutions are in the range of 2.46×10 −5 to 4.01×10 −4 s −1 and depend on the crystallite size, amount of catalyst and concentration of RhB. Photocorrosion experiments have shown the formation of Bi 2 O 2 CO 3 after several catalytic cycles. However, the catalyst can be recycled to phase‐pure β‐Bi 2 O 3 nanoparticles by annealing for one hour under argon atmosphere at 380 °C. Furthermore, the photocatalytic activity of as‐prepared β‐Bi 2 O 3 nanoparticles for the decomposition of phenol, 4‐chlorophenol, 2,4‐dichlorphenol, 4‐nitrophenol, triclosan and ethinyl estradiol is demonstrated.