WEB Patterning of TiO2 Thin Films with 3D Flower- and Hedgehog-like Au Micro- and Nanostructures for Photocatalytic and Self-Cleaning ApplicationsThursday (24.09.2020) 10:55 - 11:10 F: Functional Materials, Surfaces, and Devices 2 Part of:
Noble metal (Au, Ag, and Pt, etc.) micro- and nanostructures have been received outstanding attention during the last decades, due to their unique structural, electronic, and catalytic properties. Especially, the incorporation of these micro- and nanostructures with wide-bandgap semiconductor metal oxides such as titanium oxide (TiO2) has been shown to enhance their (photo)catalytic activity in the visible and ultraviolet (UV) irradiation as well as surface wettability properties. (Photo)catalytic and wettability properties of these hybrid structures can be finely tuned by controlling the shape and size of Au micro- and nanostructures. [2-3] There are various studies about the synthesis of micro- and nanostructures well-defined size and morphology in the literature. However, it is still a challenge to achieve good adhesion between micro- and nanostructures and metal oxide surface. Therefore, some approaches (seed-mediated growth, etc.) have been published to enhance the adhesion of Au micro- and nanostructures on metal oxide by using some binder molecules. However, these may decrease the surface conductivity and affect the photocatalytic activity of the Au micro- and nanostructures as well as controllable surface coverage and uniform structure size. Here, we demonstrate a novel photocatalytic deposition approach for preparing 3D flower- and hedgehog-like Au micro- and nanostructures on metal oxide surface by UV illumination, which leads to a strong chemical structure-substrate adhesion and well-controlled distribution of surface features. This method allows the controlling the geometry, size, and distribution of such 3D flower- and hedgehog-like Au micro- and nanostructures on metal oxide thin film by simply altering the polarity and dielectric characteristics of the deposition solution, photocatalytic activity (crystallinity and surface area) of metal oxide, UV illumination intensity and time. Special attention will be given to superhydrophilic-superhydrophobic patterning by 3D flower- and hedgehog-like Au micro- and nanostructures, which may open various application avenues in microfluidics, oil-water separation including in water harvesting technologies.
 S. Veziroglu, F. Faupel, O. C. Aktas et al. ACS Applied Materials Interfaces, 2020, 12, 14983.
 S. Veziroglu, F. Faupel, O. C. Aktas et al. Advanced Materials Interfaces, 2018, 5, 1800465.
 J. Shondo, F. Faupel, O. C. Aktas et al. Applied Surfaces Science, 2020, under consideration