Wedge-like WO3 architectures for efficient electrochromism and photoelectrocatalytic activity towards water pollutants

Abstract

The present work demonstrates the electrochromic and photoelectrochemical activity of wedge-like WO3 architecture synthesized by a low cost and facile hydrothermal technique. The optimization has been carried out through variation in hydrothermal duration. Structural and morphological characterization depicted the formation of pure phase hexagonal WO3 architectures at 180°C in 24h. The current density of dip coated WO3 onto ITO was observed to be 1mA/cm2. The fabricated electrode exhibited high coloration efficiency, fast switching characteristics (5.0s for coloration and 3.4s for bleaching) and high optical modulation. The synergistic investigation of photocatalysis and electrocatalysis on the WO3 system has been studied with respect to variation in the applied potential. The potential applied has dramatic effect on the photoelectrochemical activity and was found superior to the photocatalytic activity. Higher activity has been observed at potential 1.25V and a trend of increase in the photoelectrochemical activity with increasing potential is followed up to this voltage. A probable photoelectrochemical mechanism has been proposed. The above findings depict that WO3 wedge architecture may serve as a promising material towards application of electrochromic devices and degradation of organic pollutants.