The role of surface/interfacial Cu{sup 2+} sites in the photocatalytic activity of coupled CuO-TiO{sub 2} nanocomposites.

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Journal of Physical Chemistry. C

DOI:https://doi.org/10.1021/jp8068392· OSTI ID:986742

Li, G; Dimitrijevic, N M; Chen, L; Rajh, T; Gray, K A

Coupled CuO-TiO{sub 2} 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 Cu{sup 2+}+ sites using Cu{sup 2+} as a sensitive paramagnetic probe. The addition of bulk CuO to TiO{sub 2} 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{sub 2}. EPR study of the TiO{sub 2} surface revealed the presence of both highly dispersed CuO clusters and substitutional Cu{sup 2+} 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-TiO{sub 2} nanocomposite. In contrast, at higher loadings the bulk form of CuO created charge recombination centers lowering the photoactivity of the composites.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 986742
• Report Number(s): ANL/CSE/JA-62406
• Journal Information: Journal of Physical Chemistry. C, Journal Name: Journal of Physical Chemistry. C Journal Issue: 48 ; 2008 Vol. 112; ISSN 1932-7447
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
COPPER
DEPOSITION
EFFICIENCY
ELECTRON SPIN RESONANCE
METHYLENE BLUE
PRECIPITATION
RECOMBINATION
SPECTROSCOPY