A WO3 Nanoporous-Nanorod Film Formed by Hydrothermal Growth of Nanorods on Anodized Nanoporous Substrate

A tungsten oxide (WO 3 ) nanoporous-nanorod film was produced for the first time by hydrothermally growing WO 3 nanorods on nanoporous WO 3 substrate. The nanoporous substrates were prepared using the anodization method; hydrothermal reaction was performed on as-anodized and annealed (200–500 ◦ C) nanoporous substrates for nanorod growth. The as-anodized substrate and the substrates annealed at ≤ 300 ◦ C dissolved after hydrothermal reaction because of the amorphous and low crystallinity behaviors of the WO 3 substrates. However, the substrates annealed at ≥ 400 ◦ C did not dissolve during the hydrothermal reaction; instead, nanorods were grown on the substrates, forming a nanoporous-nanorod structure. The WO 3 nanoporous-nanorod film (nanorods grown on substrate annealed at 400 ◦ C) showed good electrochromic properties with high current density ( − 13.22 and + 7.30 mA cm − 2 ), good cycling stability, and short coloring ( ∼ 6 s) and bleaching ( ∼ 3.4 s) times. These good properties are attributed to the combination of two nanostructures (nanoporous and nanorods) that contributed to a large WO 3 surface area.

[1]  Z. Lockman,et al.  Effect of annealing temperature on anodized nanoporous WO3 , 2015, Journal of Porous Materials.

[2]  K. V. Khot,et al.  High performing smart electrochromic device based on honeycomb nanostructured h-WO3 thin films: hydrothermal assisted synthesis. , 2015, Dalton transactions.

[3]  Z. Lockman,et al.  Preparation of WO3 Nanorods by Seeded Growth Hydrothermal Reaction , 2014 .

[4]  Qiang Sun,et al.  Hydrothermal synthesis of WO3 nanorods and their performance in the adsorption of Rhodamine B and the synthesis of adipic acid , 2014 .

[5]  Guofa Cai,et al.  Growth of vertically aligned hierarchical WO3 nano-architecture arrays on transparent conducting substrates with outstanding electrochromic performance , 2014 .

[6]  K. A. Razak,et al.  WO3 nanorods prepared by low-temperature seeded growth hydrothermal reaction , 2014 .

[7]  A. Aziz,et al.  The formation of WO3 nanorods using the surfactant-assisted hydrothermal reaction , 2014 .

[8]  W. Wlodarski,et al.  Investigation of RF sputtered tungsten trioxide nanorod thin film gas sensors prepared with a glancing angle deposition method toward reductive and oxidative analytes , 2013 .

[9]  F. Zheng,et al.  Effect of substrate pre-treatment on controllable synthesis of hexagonal WO3 nanorod arrays and their electrochromic properties , 2013 .

[10]  Guofa Cai,et al.  Ultra-thin WO3 nanorod embedded polyaniline composite thin film: Synthesis and electrochromic characteristics , 2013 .

[11]  Wenjun Yan,et al.  Growth of tungsten oxide nanorods onto porous silicon and their sensing properties for NO2 , 2013 .

[12]  Sheng-Chang Wang,et al.  Characterization of electrochromic tungsten oxide film from electrochemical anodized RF-sputtered tungsten films , 2013 .

[13]  Hongwen Zhang,et al.  Layer-controlled synthesis of WO₃ ordered nanoporous films for optimum electrochromic application. , 2013, Nanoscale.

[14]  S. Zhuiykov,et al.  Anodic formation of a thick three-dimensional nanoporous WO3 film and its photocatalytic property , 2013 .

[15]  P. Schmuki,et al.  Rapid anodic formation of high aspect ratio WO3 layers with self-ordered nanochannel geometry and use in photocatalysis. , 2012, Chemistry.

[16]  S. Zhuiykov,et al.  The anodized crystalline WO3 nanoporous network with enhanced electrochromic properties. , 2012, Nanoscale.

[17]  C. Kuo,et al.  EXPERIMENTAL STUDY OF THE ELECTROCHROMIC PROPERTIES OF WO 3 THIN FILMS DERIVED BY ELECTROCHEMICAL METHOD , 2012 .

[18]  Xiuli Wang,et al.  Hydrothermally synthesized WO3 nanowire arrays with highly improved electrochromic performance , 2011 .

[19]  J. Tu,et al.  Enhanced electrochromic performance of macroporous WO3 films formed by anodic oxidation of DC-sputtered tungsten layers , 2010 .

[20]  So Yeon Park,et al.  Colloidal approach for tungsten oxide nanorod-based electrochromic systems with highly improved response times and color efficiencies , 2009 .

[21]  P. Schmuki,et al.  Enhanced electrochromic properties of self-organized nanoporous WO3 , 2008 .

[22]  J. Augustynski,et al.  Crystallographically oriented mesoporous WO3 films: synthesis, characterization, and applications. , 2001, Journal of the American Chemical Society.

[23]  A. Murayama,et al.  Characterization of evaporated amorphous WO3 films by Raman and FTIR spectroscopies , 1988 .

[24]  Jānis Kleperis,et al.  Electrochromic colour centres in amorphous tungsten trioxide thin films , 1984 .

[25]  Jinmin Wang,et al.  Construction of hydrated tungsten trioxide nanosheet films for efficient electrochromic performance , 2015 .

[26]  Hongzhi Wang,et al.  Morphology-tailored synthesis of vertically aligned 1D WO3 nano-structure films for highly enhanced electrochromic performance , 2013 .

[27]  W. Marsden.  I and J , 2012 .

[28]  P. Kajitvichyanukul,et al.  Anodic growth of nanoporous WO3 films: Morphology, photoelectrochemical response and photocatalytic activity for methylene blue and hexavalent chrome conversion , 2008 .

[29]  C. Julien,et al.  Orthorhombic WO3Formed via a Ti-Stabilized WO3·13H2O Phase , 1998 .

[30]  T. Arnoldussen.  A Model for Electrochromic Tungstic Oxide Microstructure and Degradation , 1981 .