Mesoporous Anatase TiO2 Films: Use of Ti K XANES for the Quantification of the Nanocrystalline Character and Substrate Effects in the Photocatalysis Behavior

PAULA C. ANGELOMÉ; LEANDRO ANDRINI; MAURICIO E. CALVO; FÉLIX G. REQUEJO; SARA A. BILMES; GALO J. A. A. SOLER-ILLIA

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Año: 2007 vol. 111 p. 10886 - 10893

1932-7447

Mesoporous titania thin films with accessible porosity and anatase structure were synthesized on conductive glass or silicon substrates. Ti K-edge XANES was used to assess Ti local coordination. Analysis of the pre-edge region permitted accurate quantification of the degree of crystalline nature of the inorganic walls upon thermal treatment. The substrate has a marked effect: film crystallization takes places at temperatures 100 °C lower in the crystalline Si, with respect to conductive glass. Accordingly, remarkable photocatalytic properties are found in well-crystallized mesoporous titania deposited onto conductive silicon.