Electrosynthesis and characterization of a novel electrochromic copolymer based on 1,4-bis(3-hexylthiophen-2-yl)benzene and perylene dye

An electrochromic copolymer based on 1,4-bis(3-hexylthiophen-2-yl)benzene (BHThBe) and perylene was electrochemically synthesized in dichloromethane (DCM) containing tetrabutylammonium perchlorate (TBAP) via the direct oxidation of BHThBe/perylene mixtures. The morphology and structure of as-prepared P(BHThBe–perylene) copolymer were characterized by SEM and FT-IR, respectively. The band gap energy (Eg) of P(BHThBe–perylene) in the neutral state was calculated to be 2.03 eV based on the onset of the second π–π* transition. The copolymer exhibited four different colors (brick red, grey brown, grey green, and black blue) during a wide potential ranging from 0.40 to 1.20 V. Tunable electrochromism as well as smooth morphology made this copolymer a great candidate for many applications.