Photoelectrochemistry of quantized WO[sub 3] colloids. Electron storage, electrochromic, and photoelectrochromic effects

• Published in: Journal of physical chemistry (1952) 1993-10, Vol.97:42
• Main Authors: Bedja, I., Hotchandani, S., Kamat, P.V.
• Format: Article
• Language: English
• Subjects: 360606 > Other Materials-- Physical Properties-- (1992-); 400500 > Photochemistry; CHALCOGENIDES; CHEMICAL REACTIONS; COLLOIDS; DECOMPOSITION; DISPERSIONS; DYES; ELECTRO-OPTICAL EFFECTS; ELECTROCHEMICAL CELLS; ELECTROCHROMISM; ENERGY STORAGE; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; KINETICS; MATERIALS; MATERIALS SCIENCE; OXIDES; OXYGEN COMPOUNDS; PHOTOCHEMICAL ENERGY STORAGE; PHOTOCHEMICAL REACTIONS; PHOTOELECTROCHEMICAL CELLS; PHOTOLYSIS; REACTION KINETICS; REFRACTORY METAL COMPOUNDS; SEMICONDUCTOR MATERIALS; SOLAR ENERGY; SOLAR EQUIPMENT; STORAGE; TRANSITION ELEMENT COMPOUNDS; TRAPPING; TUNGSTEN COMPOUNDS 140505 > Solar Energy Conversion-- Photochemical, Photobiological, & Thermochemical Conversion-- (1980-); TUNGSTEN OXIDES
• ISSN: 0022-3654; 1541-5740
• DOI: 10.1021/j100144a027

Electron storage effects in quantized WO[sub 3] colloids have been investigated by spectroelectrochemical and photochemical methods. Electrons trapped within the colloidal particles exhibit blue coloration with absorption in the red-IR region. From picosecond laser flash photolysis experiments, we estimate the rate constant for electron trapping to be 10[sup 10] s[sup [minus]1]. These trapped electrons are stable in an inert atmosphere and can be utilized to reduce substrates such as thiazine and oxazine dyes which have reduction potentials less negative than the conduction band of WO[sub 3]. The rate constants for the heterogeneous electron transfer at the semiconductor/electrolyte interface are in the range (0.7-2.4) [times] 10[sup 9] M[sup [minus]1] s[sup [minus]1]. 43 refs., 10 figs., 1 tab.