Electrochemical Preparation of Covalently Bonded PEDOT - Graphene Oxide Composite Electrochromic Materials Using Thiophene-2-methylanine as Bridging Group

A novel Poly (3, 4-ethylenedioxythiophene)-Graphene oxide (PEDOT-GO) composite electrochromic material containing interfacial covalent bonds was successfully synthesized by electrochemical polymerization using thiophene-2-methylanine as bridging group. The molecular structure and morphology of PEDOT-GO were studied by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical behavior and electrochromic properties of PEDOT-GO were characterized by CV (cyclic voltammetry) and UV-vis (ultraviolet-visible spectroscopy). It can be found that the electrochemical activity of PEDOT-GO is higher than that of PEDOT. Electrochromic devices using PEDOT-GO as the active layer show significant optical contrast enhancement function owing to excellent electron conduct feature of GO. While the ion blocking effects becomes more and more obvious with the increase of GO amount. As comparison with PEDOT, the contrasts of PEDOT-GO-3 %, PEDOT-GO-5 % and PEDOT-GO-7 % increase by 30 %, 64 % and 57 %, respectively.