Fabrication of 3D nanostructured ZnO and Ni electrodes for their thermoelectric, piezoelectric and electrocatalytic applications

Abstract

Nanotechnology is greatly attractive subject for many researchers due to the unique physical and chemical properties of the materials at the nanometer scale which can improve their performance in a variety of applications. Many researchers suggested that performance can be enhanced using various types of nanotechnologies such as nano-dot, nano-wire and nano-film. Unfortunately, most of them are difficult to use in real life because of their limitations of size. In this regard, studies using 3D nanostructures have attracted attention in that nanotechnology not only can improves performance in applications but also can be extended to practical use. However, the conventional method for fabricating 3D nanostructure such as layer-by-layer stacking of 2D nanostructures, forming irregular 3D porous nanostructures by utilizing gas and others has a problem in that it takes a lot of time and resources. In recent year, 3D nanopatterning techniques have been developed to fabricate 3D nanostructures in a fast, simple and reliable. Among them, the Proximity field nanoPatterning (PnP) technique use a phenomenon of optical interferences when light is transmitted through a 2D periodic nanostructures on phase mask to form a 3D nanopattern. In this dissertation, 3D nanostructures were applied to thermoelectric, piezoelectric and electrocatalytic applications. Firstly, the materials that can improve the performance through the 3D nanostructure were selected. After that, the selected materials were coated or deposited by atomic layer deposition (ALD) or electrodeposition on the 3D nanostructured polymer which is generated by PnP process as a template. And then, removing process were conducted. Finally, using 3D functional nanomaterials, the improvement of performance that can be expressed in nano-dots, nano-wires and nano-films ha been secured in a 3D nanostructure. These studies are meaningful in that they have established a bridgehead for bringing nanotechnology to practical use.