Engineering conformal nanoporous polyaniline via oxidative chemical vapor deposition and its potential application in supercapacitors

Abstract

Oxidative chemical vapor deposition (oCVD) offers unique advantages in synthesizing and integrating conducting polymers, like polyaniline (PANI), over conventional solution-based techniques, among them its ability to achieve thin films, conformal and uniform coatings, and coatings on topologically complex substrates. In this work, PANI was synthesized by oCVD via oxidative polymerization using aniline monomer and antimony pentachloride oxidant. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) confirm the formation of PANI. Uniquely, as evidenced by scanning electron microscopy (SEM) and atomic force microscopy (AFM), oCVD PANI shows a rough nanoporous morphology with pore openings of around 20 nm, while maintaining the conformality and uniformity of the coating. This nanoscale porosity leads to greater surface area that enhanced the energy storage capacity of non-porous electrospun carbon nanofibers (CNFs). With a coating thickness of ∼160 nm on CNFs, the oCVD PANI-CNF composite shows high specific capacitance and excellent cycling stability, and demonstrates the potential for porous oCVD PANI to enhance supercapacitor energy storage and power density.