Molybdenum doping effects on photochromic properties of WO₃ based composite films

Abstract

Mo-doped tungsten-based photochromic composite films were fabricated using a peroxoisopolytungstic acid methanol solution, peroxoisopolymolybdenum acid methanol solution, and transparent urethane resin. The non-doped composite films showed photochromic properties by UVVis light irradiation. The reaction rate constant was 2.68 © 10 ¹2 min ¹1 . The increasing Mo/W ratio in the film caused a blue shift of the absorption peak of the film. The reaction rate constants k of films with Mo/W rates of 0.1, 0.5, and 1.0 were 3.00, 4.23, and 3.53 © 10 ¹2 min ¹1. Those values were larger than that of a non-doped film. All composite films showed a reversible photochromic property, which was the coloring and bleaching property.

Enhanced photochromic performance of Zn-doped W18O49-based films for smart windows

“…Among TMOs, WO 3 is a typical photochromic material, but its application is limited by its slow light response and poor reversibility. In order to overcome these limitations, various strategies including structural modification, 12 hybrid material construction, [13][14][15] and element doping [16][17][18][19][20] have been employed. The main objective of these strategies is to enhance the mobility of carriers and protons in WO 3 , thereby improving its photochromic performance.…”

“…Recently, oxygen vacancy engineering has been used to regulate the structure and properties of TMOs. 21 As another tungsten oxide, W 18 O 49 with a rich oxygen defect structure has attracted much attention. The lattice distortion caused by residual electrons and oxygen vacancies in the lattice significantly affects the optical absorption characteristics and electron-hole generation ability of TMOs, 22 and its photochromic performance is expected to exceed those of traditional TMOs such as WO 3 .…”

Highly Tuneable Photochromic Sodalites for Dosimetry, Security Marking and Imaging

“…[13] The majority of photochromic binary transition metal oxides change from a pale yellowbrown to deep blue-black, the result of photoreduction or photo-oxidation followed by a charge transfer. [10,[14][15][16][17][18] Metastable Fcenter formation in vacancies is also a common mechanism for inorganic photochromic materials, and such systems are present in a range of rare-earth activated materials capable of changing from white to purple, blue, green and yellow. [19][20][21][22][23][24][25][26] The F-centervacancy mechanism is also found in natural photochromic minerals such as hackmanite, tugtupite and scapolite, [27][28][29] which are aluminosilicates mostly used for decorative purposes, but which in recent years have sparked interest for a plethora of potential applications.…”

Optimized sol-gel synthesis of WO3 hydrogel for obtaining electrochromic films

“…Н анопорошки и пленки на основе WO 3 широко применяют при разработке электро- [1][2][3] и фотохромных [4][5][6] дисплеев, оптических модуляторов [7,8], окон с регулируемым светопропусканием [9], создании резистивных [10] и полупроводниковых [11] сенсоров взрывоопасных (Н 2 , C x C H y ) и экологически вредных (CO, NO 2 и др.) газов, конструировании различных катализаторов и др.…”