PEDOT hollow nanospheres for integrated bifunctional electrochromic supercapacitors

Monodisperse silica (SiO2) with an average diameter of 67 nm was synthesized by modified stober method. Monodisperse silica/poly(3,4-ethylenedioxythiophene) (SiO2/PEDOT) core/shell nanospheres were prepared by chemical oxidative polymerization. The PEDOT hollow nanospheres were successfully synthesized by etching the SiO2/PEDOT nanospheres with hydrofluoric acid (HF). The PEDOT hollow nanospheres were used for smart electrochromic supercapacitors for the first time. Compared with dense PEDOT film, the PEDOT hollow nanosphere film exhibit larger optical contrast, fast response speed, higher coloration efficiency and large specific capacitance. More importantly, the level of stored energy could be simultaneously monitored by the rapid and reversible color variation. The PEDOT hollow nanospheres show promising applications for integrated electronic and optoelectronic devices.