V2O5 nanobelts via a facile water-assisted strategy boosting electrochromic performance

Vanadium pentoxide (V2O5) has an open layered structure with vanadium ions in various oxidation states, displaying great potential for application in electrochromic. Herein, one-dimensional (1D) V2O5 nanobelts were successfully synthesized using a facile water-assisted strategy of stirring and sonicating in water without adding any other chemical reagents. The V2O5 nanobelts are lengths of a few micrometers and widths of tens of nanometers, especially, displayed expanded layered structure with a d-spacing of 11.7 Å, accelerating the Li+ diffusion kinetics. The electrochromic property of the V2O5 nanobelts film was investigated. It demonstrates that V2O5 nanobelts are multicoloured electrochromic (yellow, yellow-green, and steel grey) with high transmittance modulation (54.8% at 427 nm), fast response time (9.0 s for bleaching and 2.7 s for coloring at 427 nm), and long cycle stability (1000 cycles). The electrochromic device based on V2O5 nanobelts also exhibits outstanding transmittance modulation and fast response time. This work develops a green large-scale preparation method to synthesize outstanding V2O5-based electrochromic materials.