Covalently Bonded Polyaniline−TiO₂ Hybrids: A Facile Approach to Highly Stable Anodic Electrochromic Materials with Low Oxidation Potentials

Abstract

In this article, we report the synthesis, structures, morphologies, and electrochromic properties of covalently bonded polyaniline (PANI)−TiO 2 hybrids. The hybrids were synthesized via a sol−gel process, followed by oxidative polymerization, using a bifunctional compound to bridge the two phases. In comparison with PANI, the hybrids show significant enhancement in optical contrast and coloration efficiency. Furthermore, when covalently bonded to PANI, the TiO 2 nanodomains can act as electron acceptors, reducing the oxidation potential and band gap of PANI, and improving the long-term electrochromic stability.