Solvothermal synthesis of tungsten oxide mesocrystals and their electrochromic performance

•W18O49 mesocrystals were synthesized using a solvothermal method.•The W18O49 mesocrystals are built from individual single-crystalline nanowires.•The W18O49 mesocrystals exhibited stable and reversible electrohcromic performance.

Flower-like W18O49 mesocrystals built from individual single-crystalline nanowires were fabricated using a facile solvothermal method. The as-prepared W18O49 mesocrystals have been systematically characterized by X-ray diffraction, energy dispersive spectroscopy, electron microscopy, selected area electron diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. Based on the analyses of cyclic voltammetric curves and UV–vis transmittance spectra, the W18O49 mesocrystals have been found to exhibit stable and reversible electrochromic performance with high color contrast, which can be attributed to their hierarchical architecture, special tunnel structure, and non-stoichiometric characteristics. The novel W18O49 mesocrystals are promising electrochromic candidate for potential application in smart window.

Graphical abstractImages of W18O49 mesocrystals and a real chrysanthemum. Figure optionsDownload full-size imageDownload as PowerPoint slide