Dual electrochromic film based on WO3/polyaniline core/shell nanowire array

The WO3/PANI core/shell nanowire array is prepared by the combination of solvothermal and electropolymerization methods. The core/shell nanowire array film shows remarkable enhancement of the electrochromic properties. In particular, a significant optical modulation (59% at 700nm), fast switching speed, high coloration efficiency (86.3cm2C−1 at 700nm) and excellent cycling stability are achieved for the core/shell nanowire array film. The improved electrochromic properties are mainly attributed to the formation of the donor–acceptor system, and the porous space among the nanowires, which can make fast ion diffusion and provide larger surface area for charge-transfer reactions. The data indicate great promise for the WO3/PANI core/shell nanowire array as a potential multicolor electrochromic material. [Display omitted] •The WO3/PANI core/shell nanowire array is successfully prepared.•The dual-electrochromism effect is obtained for the core/shell nanowire array.•The core/shell structure exhibits large optical modulation and fast switching speed.•High CE and excellent cycling stability are achieved for the core/shell structure.