Cibrev Dejan, Jankulovska Milena, Lana-Villarreal Teresa, Gómez Roberto
Institut Universitari d'Electroquímica i Departament de Química Física, Universitat d'Alacant , Apartat 99, E-03080 Alicante, Spain.
ACS Appl Mater Interfaces. 2014 Jul 9;6(13):10304-12. doi: 10.1021/am5017396. Epub 2014 Jun 26.
In the field of energy saving, finding composite materials with the ability of coloring upon both illumination and change of the applied electrode potential keeps on being an important goal. In this context, chemical bath deposition of Ni(OH)2 into nanoporous TiO2 thin films supported on conducting glass leads to electrodes showing both conventional electrochromic behavior (from colorless to dark brown and vice versa) together with photochromism at constant applied potential. The latter phenomenon, reported here for the first time, is characterized by fast and reversible coloration upon UV illumination. The bleaching kinetics shows first order behavior with respect to the Ni(III) centers in the film, and an order 1.2 with respect to electrons in the TiO2 film. From a more applied point of view, this study opens up the possibility of having two-mode smart windows showing not only conventional electrochromism but also reversible darkening upon illumination.
