title: An investigation of nanostructured rutile and anatase plates for improving the photosplitting of water.
abstract: Developing new semiconductor materials for improving photocatalytic reactivity is important for solving the challenging environmental and energy problems we are facing today. This work focuses on increasing the quantum efficiency in titania photocatalysts for photocatalytic (oxidation of acetaldehyde) and photosynthetic (photosplitting of water) reactions by synthesizing pure phase rutile and anatase nanostructures with well defined morphologies and investigating their photocatalytic performance compared to a commercial titania photocatalyst (Degussa P25). Nanostructured anatase is dominated by {100} surfaces with a small amount of {101} surfaces, whereas the rutile nanoplates consist of nanorods dominated by {110} and {111} crystal surfaces. In accordance with the signals from electron spin resonance (ESR) spectra, both nanostructured anatase and rutile phases have high photocatalytic activity for photosplitting of water compared to P25 titania. The anatase phase shows a high activity for photocatalytic oxidation (PCO) of acetaldehyde whereas the rutile phase shows a lower activity. The results of these experiments basically agree with previously published works that reported that the oxidation and reduction sites on rutile particles are on the {011} and {110} faces respectively, and on {001} and {011} faces respectively for anatase particles. The results have important implications for enhancing the photocatalytic activity of titania for environmental remediation, increasing the quantum efficiency in photo-voltaic (PV) solar cells and other photo-assisted processes.
authors.affiliation: Department of Geology and Geophysics, and Materials Science Program, University of Wisconsin, 1215 W Dayton Street, Madison, WI 53706, USA.
authors.forename: Rakesh R
authors.initials: RR
authors.lastname: Yeredla
authors.forename: Huifang
authors.initials: H
authors.lastname: Xu