Facile synthesis of anatase-rutile TiO2 composites with enhanced CO2 photoreduction activity and the effect of Pt loading on product selectivity

摘要

A facile and surfactant-free peroxo-titanium sol-gel route has been developed to synthesize TiO2 composites with a two-phase mixture of anatase and rutile at 350 degrees C. Thermal analysis revealed that the anatase to rutile phase transformation occurs at ca. 325 degrees C. The absorption edge of the obtained two-phase TiO2 is red-shifted to ca. 420 nm, and its photocatalytic performance on CO2 reduction is on a par with TiO2 P25. To further enhance the photocatalytic activity, 0.1 mass% Pt was loaded by photoelectrodeposition, which led to a high CO2 photoreduction efficiency with selective formation of methane. The synthesis method is useful to fabricate composites containing anatase-rutile TiO2 and high-temperature sensitive substances such as carbon nanomaterials. (C) 2015 Elsevier B.V. All rights reserved.