The optical absorption edge of brookite TiO2
نویسنده
چکیده
The optical absorption edge of brookite TiO2 was measured at room temperature, using natural crystals. The measurements extend up to 3.54 eV in photon energy and 2000 cm in absorption coefficient. The observed absorption edge is broad and extends throughout the visible, quite different from the steep edges of rutile and anatase. No evidence of a direct gap is seen in the range measured. The spectral dependence of the absorption strongly suggests that the brookite form of TiO2 is an indirect-gap semiconductor with a bandgap of about 1.9 eV. q 2005 Elsevier Ltd. All rights reserved. PACS: 78.40.Fy; 78.20.Ci; 71.20.Kb
منابع مشابه
Ti3+-self doped brookite TiO2 single-crystalline nanosheets with high solar absorption and excellent photocatalytic CO2 reduction.
Black brookite TiO2 single-crystalline nanosheets with outstanding photocatalytic activity toward CO2 reduction is prepared by a facile oxidation-based hydrothermal reaction method combined with post-annealing treatment. Large amount of Ti(3+) defects are introduced into the bulk of brookite nanoparticles, which increases the solar energy absorption and enhances the photocatalytic activity.
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