Described is the construction of an ultrafast electrochromic window. One electrode of this window is based on a transparent nanostructured TiO 2 (anatase) film (4.0 µm thick) supported on conducting glass (F-doped tin oxide, 10 Ω cm -2 , 0.5 µm thick) and modified by chemisorption of a monolayer of the redox chromophore bis(2-phosphonoethyl)-4,4′-bipyridinium dichloride. The other electrode is based on a transparent nanostructured SnO 2 film (3.0 µm thick) supported on conducting glass (F-doped tin oxide, 10 Ω cm -2 , 0.5 µm thick) and modified by chemisorption of a monolayer of the redox chromophore [β-(10-phenothiazyl)propoxy]phosphonic acid. The electrolyte used is LiClO 4 (0.2 mol dm -3 ) in γ-butyrolactone. The excellent performance of a 2.5 cm × 2.5 cm window over 10 000 electrochromic test cyclessswitching times (coloring and bleaching) of less than 250 ms, coloration efficiency of 270 cm 2 C -1 , steady-state currents (colored and bleached) of less than 6 µA cm -2 , and memory of greater than 600 s (time required for low end transmittance to increase by 5%)ssuggest a practical technology.

In the absence of a dopant or precursor modification, anatase to rutile transformation in synthetic TiO 2 usually occurs at a temperature of 600 ºC to 700 ºC. Conventionally, metal oxide dopants (e.g. Al 2 O 3 and SiO 2 ) are used to tune the anatase to rutile transformation. A simple methodology is reported here to extend the anatase rutile transformation by employing various concentrations of urea.XRD and Raman spectroscopy were used to characterize various phases formed during thermal treatment. A significantly higher anatase phase (97%) has been obtained at 800 ºC using a 1:1 (Ti (OPr) 4 : urea) composition and 11% anatase composition is retained even after calcining the powder at 900 ºC. On comparison a sample which has been prepared without urea showed that rutile phases started to form at a temperature as low as 600 °C. The effect of smaller amounts of urea such as 1:0.25 and 1:0.5 (Ti (OPr) 4 :urea) has also been studied and compared. The investigation concluded that the stoichiometric modification by urea 1:1 (Ti (OPr) 4 :urea) composition is most effective in extending the anatase to rutile phase transformation by 200 ºC compared to the unmodified samples. In addition, BET analysis carried out on samples calcined at 500 °C showed that the addition of urea up to 1:1 (Ti (OPr) 4 :urea) increased the total pore volume (from 0.108 cm 3 /g to 0.224 cm 3 /g) and average pore diameter (11 nm to 30 nm) compared to the standard sample. Samples prepared using 1:1 (Ti (OPr) 4 :urea) composition calcined at 900 ºC show significantly higher photocatalytic activity compared to the standard sample prepared under similar conditions. Kinetic analysis shows a marked increase in the photocatalytic degradation of rhodamine 6G on going from the standard sample (0.016 min , decoloration in 50 mins).

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A straightforward and industria 2 lly viable synthesis for mesoporous nanocrystalline titania in electrochromic displays has been achieved using titanium butoxide, deionised water and butanol at a low microwave power intensity (300 W, 2 min) irradiation.ART B924341K_GRABS The fabrication of paper quality electrochromic displays based on the viologen modified TiO 2 electrodes (Vio 2+ /TiO 2 ) requires a cost-effective, energy efficient and rapid synthesis of mesoporous TiO 2 with high yield in short reaction time. A straightforward and industrially viable process for the preparation of mesoporous nanocrystalline titania (meso-nc-TiO 2 ) for NanoChromicsÔ display device applications by the use of microwave synthesis is presented here. Spherical aggregates of meso-nc-TiO 2 were rapidly achieved using titanium butoxide, deionised water and common alcohols (isopropanol, ethanol and butanol) at comparatively low microwave power intensity (300 W) for 2 min irradiation. The material has been characterised by a range of different techniques such as XRD, Raman spectroscopy, SEM and BET surface area analysis. These materials possess surface areas up to 240 m 2 g À1, which is significantly higher than similar traditional sol-gel or commercial samples. This meso-nc-TiO 2 prepared was used as the working electrode for an electrochromic display device with Sb doped SnO 2 as the counter electrode material on an ITO coated conducting glass. A working prototype of a NanoChromicsÔ display was successfully fabricated using this approach.