Preparation of WO₃nanorods by a hydrothermal method for electrochromic device

Abstract

Uniform WO3 nanorods were prepared by a hydrothermal process, and the synthesis was accomplished by using NaCl as the capping agent and Na2WO4 as the inorganic precursor. Scanning electron microscopy, X-ray diffractometer, transmission electron microscopy and UV–visible spectroscopy were used to characterize the morphology, phase, and nanostructure of the resulting nanorods. The effects of pH and the amount of NaCl capping agent on the morphology of the WO3 nanorods were investigated. Uniform and regular aligned WO3 nanorod films can be achieved by self-assembly in a drop coating process. Moreover, the electrochromic devices based on WO3 nanorods display a deep blue color and have low transmittance (<2%) in the colored state, especially in the infrared range, which may provide a promising platform for energy-saving smart windows, and other electro-optical applications.