Preparation of a PB@SiO2 Photonic Crystal Composite with Enhanced Electrochromic Performance

SiO2 photonic crystals are employed as a template to prepare composite films of Prussian blue (PB) on a SiO2 photonic crystal (PB@SiO2) by a facile method. The surface morphology and crystallinity are characterized, and the optical, electrochemical, and electrochromic properties are measured. Compared with the pure PB film, the redox ability of the PB@SiO2 composite film increases. In addition, the composite displays a maximum contrast as high as 49.1%, accelerated coloration, and bleaching response times of 3.4 and 6.1 s relative to those of the pure PB. Moreover, the cyclic stability of the PB@SiO2 composite film is also enhanced. Results show that the electrochromic function can be significantly improved by judicious construction of the core–shell structure of PB@SiO2, which may open an avenue to fabricate high-performance electrochromic composites and facilitate their applications.