We have developed a new electrode design comprised of a single layer, carbon-free, unsupported, multifunctional catalyst nanorod arrays with extremely low loadings, controlled hydrophobicity, and reduced CO poisoning. We used glancing angle deposition (GLAD) technique for the growth of nanorod arrays. These nanorods can be assembled directly on to the PEM or the gas diffusion layer. Our group also has started to systematically study electrochemical and hydrophobic properties of these glancing angle deposited multifunctional nanorods, their resistance to CO poisoning, effects of nanorod diameter, length, and separation on such properties, and finally their fuel cell electrode performances. We also started computational modeling studies to better understand/optimize the nanostructure growth. Our proposed work is believed to the development of new nanoscale electrode-catalyst structures which enhances the electrochemical activity, does not contain carbon, can be utilized in low loadings, provides desired hydrophobic properties, avoids CO poisoning, and has the potential to maximize the power/effective surface area of the catalyst. By this way, we plan to avoid the problems associated with conventional carbon supported Pt nanoparticles or issues related to polycrystalline continuous Pt thin film approaches.
In addition, we successfully introduced a hydrophobic property to vertically aligned hydrophilic platinum nanorods. The Pt nanorod arrays were deposited on flat silicon substrates using GLAD next a thin layer of Teflon (nanopatch) was partially deposited on the tips of platinum nanorods. Contact angle measurements on nanocomposite Pt nanorods with Teflon nanopatches exhibited contact angle values as high as 138, indicating a significant increase in the hydrophobicity of originally hydrophilic Pt nanostructures that had an angle of about 52.