AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Effect of Shape of Au Nanoparticles on the Photoelectrochemical Water-Splitting Performance of Au-TiO2 Nanocomposite Thin Films
TANDEEP CHADHA, Jinho Park, Woo-Jin An, Pratim Biswas, Washington University in St. Louis
Abstract Number: 414 Working Group: Synthesis of Functional Materials using Flames, Plasmas and other Aerosol Methods
Abstract Au-TiO2 composited thin films have received considerable attention due to the surface plasmonic nature of Au nanoparticles (Liu et al. 2011). Controlling the size of the nanoparticles simultaneously changes both the surface plasmon resonance (SPR) and the interfacial contact area between Au and TiO2. Hence independent contribution of these factors on the performance is not yet known. These two factors can be decoupled by changing the shape of the particles since it is known that Au particles of different shapes exhibit varied SPR behavior.
This study focuses on the effect of the shape of Au nanoparticles on the photoelectrochemical performance of Au-TiO2 composited thin films. Columnar TiO2 thin films were synthesized by the Aerosol-Chemical Vapor Deposition (ACVD) technique (An et al. 2009). Au nanoparticles of various shapes, including spheres, nanocages and nanorods, synthesized by liquid phase methods using a stabilizing agent were deposited onto these films by spin coating. The performance of these composited photoelectrodes was evaluated using a three electrode system in a quartz cell under illumination by an Arc Xe lamp. Preliminary results show that the saturated photocurrent density decreased from 4.3 mA cm-2 to 3.5 mA cm-2 when spherical Au particles of size 5 nm stabilized by citrate were deposited on the TiO2 thin films. The weak interaction between the citrate and the gold surface in a highly alkaline environment (Lana-Villarreal and Gómez 2005) caused the decreased performance. The performance of Au nanocages and Au nanorods stabilized by different stabilizing agents will be further explored. A description of the charge separation mechanism will be discussed.
References:
An, W.-J., Thimsen, E. and Biswas, P. (2009). Aerosol-Chemical Vapor Deposition Method For Synthesis of Nanostructured Metal Oxide Thin Films With Controlled Morphology. The Journal of Physical Chemistry Letters 1:249-253.
Lana-Villarreal, T. and Gómez, R. (2005). Interfacial electron transfer at TiO2 nanostructured electrodes modified with capped gold nanoparticles: The photoelectrochemistry of water oxidation. Electrochemistry Communications 7:1218-1224.
Liu, Z., Hou, W., Pavaskar, P., Aykol, M. and Cronin, S. B. (2011). Plasmon Resonant Enhancement of Photocatalytic Water Splitting Under Visible Illumination. Nano Letters 11:1111-1116.