Synthesis of nickel oxide nanostructures for the application of smart windows

Abstract

Nickel Oxide is a very well known anodic electrochromic oxide used in an ECD. Nickel oxide nanostructures have received huge attention because of its several properties, i.e. high (and low) transparency of colored and bleached (and colored) state, fast coloration and bleaching times; and good coloration efficiency. Nanostructures offer a larger surface area and more capillary pathways for the ion insertion and deinsertion. Because of the insertion and deinsertion of anions with NiO nanostructures of thin films, bleaching and coloration takes place In this research work, we have demonstrated the two different types of nanostructures synthesized by the physical and chemical method. HFMOVD and hydrothermal method are the physical and chemical method used for this work. Nanobelts were obtained from Hydrothermal method, and thin films were synthesized by the physical method. The characterization of these samples and performance tests from which we have obtained the electrochromic properties. The coloration efficiency is ~74% and for the physically synthesized samples are ~13 % at ~354 nm. The coloration and bleaching times at this wavelength are 2-6 seconds and 0.39-0.45 seconds respectively.