|Title:||Visible-light response Cr-doped TiO2-XNX photocatalysts||Authors:||Pan, Chien-Cheng
Wu, Jeffrey C.S.
|Keywords:||Photocatalyst;Sol–gel;Titania;Cr and N doping||Issue Date:||2006||Publisher:||Taipei:National Taiwan University Dept Chem Engn||Journal Volume:||100||Journal Issue:||1||Start page/Pages:||102-107||Source:||Materials Chemistry and Physics||Abstract:||
Chromium (Cr) and nitrogen (N)-doped titania (TiO2) was prepared using sol–gel method and ammonia thermal treatment. TiO2 co-doped
with Cr and N showed intense absorption bands in the visible-light region. The X-ray photoelectron spectroscopy (XPS) detected chromium
and nitrogen ions on the surface of catalysts, but no diffractive peak of chromium oxide or titanium nitride was observed in X-ray diffraction
(XRD) spectra. The analysis of X-ray absorption near edge spectroscopy (XANES) indicated either Cr3+ or Cr4+ chemical status implying that
chromium either substituted Ti4+ site or locally was isolated on the surface of TiO2. The photocatalytic activity was evaluated by the degradation
of methylene blue (MB) and isopropyl alcohol (IPA) under visible-light (>460 nm) irradiation using blue-light emitted diode. The rate constants
of MB and IPA photodegradation with N-doped TiO2 were 7.7 and 80 mol l−1 h−1 g−1, which were much higher than those with pure TiO2, 0.15
and 0 mol l−1 h−1 g−1, respectively. The Cr and N co-doped TiO2 showed less photoactivity than either Cr or N-doped TiO2 due to the extra
imperfection of TiO2 lattice during preparation.
|Appears in Collections:||化學工程學系|
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