PEDOT nanoparticles fully covered on natural tubular clay for hierarchically porous electrochromic film

In this work, we develop a facile and feasible strategy to prepare natural tubular clay halloysites nanotubes (HNT)@poly(3,4-ethylenedioxythiophene) (PEDOT) nanocomposites as an electrochromic material. The HNT@PEDOT nanocomposites were formed by coating PEDOT on the outer surface of HNT through in-situ chemical oxidative polymerization. Due to the hollow tubular and hierarchical porous structure of the hybrid nano composites, the surface area of active materials is enlarged and the diffusion distance of ions is shortened. Consequently, the HNT@PEDOT film delivers higher optical contrast (59.3%), coloration efficiency value (174.3 cm(2)/C) and long-cycle stability compared to pure PEDOT film. Besides, the as-prepared solution processable electrochromic material enables the utilization of printing or spraying methods and applies for large area and patterned films.