Methyl triphenylphosphonium permanganate as a novel oxidant for aniline to polyaniline-manganese(II, IV) oxide: material for high performance pseudocapacitor

Abstract

In this work, organic-inorganic composite materials of polyaniline and manganese oxide were synthesized and investigated their electrochemical performance. This composite material was prepared by oxidizing aniline with methyl triphenylphosphonium permanganate as a novel organic oxidant via aqueous, emulsion, and interfacial polymerization pathways. This process led to the formation of polyaniline-sulfate salt (PANI-SA-Mn5O8). Formation of polyaniline-sulfate salt was confirmed from FT-IR, EDAX, and XRD results. Formation of Mn5O8 was supported by XRD spectrum. PANI-SA-Mn5O8 prepared via emulsion polymerization pathway was obtained in porous nanorod morphology with high conductivity (9.4 S cm−1) compared to that of the other sample prepared via interfacial pathway (1.7 S cm−1). Whereas, aqueous polymerization pathway resulted in sheet-like morphology with a conductivity of 0.8 S cm−1. These composites were used as pseudocapacitive electrode materials. Electrochemical characterization (cyclic voltammetry, charge-discharge, and electrochemical impedance measurement) showed that composite prepared via emulsion polymerization pathway gave better electrochemical performance, and showed good cycling behavior.