AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Highly Efficient Pt-TiO2 Nanostructured Films for CO2 Conversion to Hydrocarbon Fuels
WEI-NING WANG, Woo-Jin An, Balavinayagam Ramalingam, Somik Mukherjee, Dariusz M. Niedzwiedzki, Shubhra Gangopadhyay, Pratim Biswas, Washington University in St. Louis
Abstract Number: 360 Working Group: Nanoparticles and Materials Synthesis
Abstract A facile development of highly efficient platinized titania (Pt-TiO2) nanostructured films via versatile gas phase deposition methods is described. The films have one-dimensional (1D) structure of TiO2 single crystals, deposited by an aerosol chemical vapor deposition route, which is a continuous and low energy method designed to deposit metal oxide films with controlled morphologies. Platinum nanoclusters (NCs) were coated onto the TiO2 single crystals using a unique tilted target sputtering method. Ultra-small Pt sizes ranging from 0.5 to 2 nm with uniform distribution could be finely tuned which are not readily achieved and controlled using conventional liquid phase synthesis methods. These Pt-TiO2 nanostructures demonstrated high photoreduction efficiency with selective CH4 formation. The size of the Pt nanoclusters plays an important role in the CO2 photoreduction process. The mechanistic pathways of CO2 photoreduction have been explained in detail. The high surface area and single crystallinity of the TiO2 single crystals and the efficient electron-hole separation by the Pt NCs were the main reasons attributable for the enhancement, which have been confirmed by experimental results including femtosecond time-resolved transient absorption spectroscopy measurements.