Abstract
Coupled CuO-TiO2 nanocomposite photocatalysts were prepared by a deposition precipitation method and were characterized with a variety of techniques. Electron paramagnetic resonance (EPR) spectroscopy was employed to study the local structures of surface/interfacial Cu2+ sites using Cu2+ as a sensitive paramagnetic probe. The addition of bulk CuO to TiO2 led to decreased photocatalytic efficiency in the degradation of methylene blue. However, doping with a very small amount of CuO (0.1 wt % copper loading) significantly enhanced the photocatalytic activity of TiO 2. EPR study of the TiO2 surface revealed the presence of both highly dispersed CuO clusters and substitutional Cu2+ sites (Ti-O-Cu linkages) at 0.1 wt % copper loading. The data suggest that the Ti-O-Cu linkages contributed to the improved photooxidative activity of the 0.1% CuO-TiO2 nanocomposite. In contrast, at higher loadings the bulk form of CuO created charge recombination centers lowering the photoactivity of the composites.
Original language | English (US) |
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Pages (from-to) | 19040-19044 |
Number of pages | 5 |
Journal | Journal of Physical Chemistry C |
Volume | 112 |
Issue number | 48 |
DOIs | |
State | Published - Dec 4 2008 |
Externally published | Yes |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- General Energy
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films