Enhanced Oxidation Stability of VO2 by Coating SiO2 Layer for Smart Window Applications

Abstract

SiO2-coated W-VO2(M) nanoparticles were synthesized by a precipitation method and then modified with tetraethylorthosilicate as a precursor using the Stober process, to enhance oxidation stability. W-VO2(M) nanoparticles were uniformly coated with a SiO2 layer approximately 25 nm in thickness. Based on XRD and DSC characterization, the crystal structure and phase transition temperature of SiO2-coated W-VO2(M) are almost the same as before SiO2 coating. Upon exposure to 80% water vapor pressure at 80 degrees C, the coated nanoparticles maintain their structure, phase transition temperature, and morphology for a longtime compared to uncoated W-VO2(M) particles, and show improved oxidation stability.