Sol–gel fabrication of WO₃/RGO nanocomposite film with enhanced electrochromic performance

Abstract

Tungsten trioxide/reduced graphene oxide (WO 3 /RGO) nanocomposite film was fabricated by the sol-gel spin coating technique, using a mixed colloidal dispersions of WO 3 precursor and GO. The structure, surface morphology and optical properties of the WO 3 and WO 3 /RGO films were investigated by means of X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, highresolution transmission electronmicroscopy and UV-visible spectrophotometer. The electrochemical and electrochromic performance of the WO 3 and WO 3 /RGO films were studied by chronoamperometry, in-situ optical transmittance and cyclic voltammograms analysis. In the WO 3 /RGO nanocomposite film, monoclinic WO 3 nanoparticles were grafted onto the surface of RGO sheets via C-W and C-O-W chemical bonds. The results showed that WO 3 /RGO nanocomposite film exhibited shorter coloration-bleaching times (t c = 9.5 s and t b = 7.6 s), higher coloration efficiency (75.3 cm 2 C -1 at 633 nm), larger optical modulatory range (59.6% at 633 nm) and better cyclic stability compared with WO 3 films, which are attributed to faster Li + ion diffusion and electron transfer rate. The methodology provides a facile and industrially scalable approach to obtain fast switching electrochromic materials.

Boosting Transport Kinetics of Ions and Electrons Simultaneously by Ti3C2Tx (MXene) Addition for Enhanced Electrochromic Performance

“…Also, the element doping introduces the oxygen vacancies which is beneficial to ionic conductivity. On the other hand, hybrid tungsten oxide film with other nanomaterials, like reduced graphene oxide (rGO) [29][30][31], carbon nanotubes (CNT) [32,33], and g-C 3 N 4 [34] have been investigated with enhanced electrochromic performance. These additives all own high-electronic conductivity and large surface area that the transport of electrons is facilitated.…”

Effect of the Ammonium Tungsten Precursor Solution with the Modification of Glycerol on Wide Band Gap WO3 Thin Film and Its Electrochromic Properties

“…The coloration efficiency (CE) value of sample was calculated to be 46.3 cm 2 •C −1 for WO3 thin films annealed at 400 °C in this work, as shown in Figure 8b. In general the CE value of sol-gelprepared films ranges from 25 cm 2 •C −1 to 75 cm 2 •C −1 , which shows that the CE value of sol-gel-free WO3 films as reliable as normal sol-gel WO3 films [37,52]. Further studies will be done about the electrical resistance and the electrochromic reliability.…”

“…Optical Band Gap(eV) Coloration Efficiency (cm 2 /C) [5] DC magnetron sputtering Amorphous 3.51 40.5 [37] Sol-gel Amorphous 3.31 45.3 [37] Sol-gel Crystalline 3.10 27.4 [52] Sol-gel Crystalline 3.01…”

Controllable factors affecting the epitaxial quality of $$\hbox {LaCoO}_{3}$$ LaCoO 3 films grown by polymer-assisted deposition

“…Polymer-assisted deposition (PAD) is a simple and costeffective technique to prepare various metal-oxide epitaxial films comparing with traditional physical or chemical vapour depositions [1,2], radio-frequency sputtering [3], molecular beam epitaxy [4] and pulsed laser deposition (PLD) [5], which need complicated equipment and have the difficulty of making large-area films. Among the aqueous solution deposition techniques, sol-gel [6,7], metal-organic deposition [8], chemical solution deposition [9] and electrochemical deposition [10] were reported to prepare epitaxial films, but many metal oxides cannot be deposited and sometimes the stoichiometry and uniformity are out of control effortlessly owing to differences in chemical reactivity among the metals [11]. The PAD method is a new aqueous solution deposition technique for growth of epitaxial film.…”