Development of Candle Soot Based Carbon Nanoparticles (CNPs)/Polyaniline Electrode and Its Comparative Study with CNPs/MnO2 in Supercapacitors

In this article we report a facile method to create a polyaniline (PANI) nanorod/carbon nanoparticle (CNP) composite structure that is suitable for supercapacitor use. A network of CNPs was conveniently produced on the surface of a nickel foam by collecting candle soot above a burning candle. The PANI nanorods were then electrochemically deposited on the CNP network, forming a star-like interconnected 3D structure. As a comparison, MnO2 particles were also deposited on the CNP network to produce a broccoli-like structure. The electrochemical properties of these two composites were examined using cyclic voltammetry, cyclic charge-discharge, and electrochemical impedance spectroscopy. The two electrodes exhibited different electrochemical behaviors: high capacitance at low current densities and marked deterioration at high ones for CNPs/PANI and relatively low but stable capacitance for CNPs/MnO2. The reasons for this distinction were discussed based on the structures and material properties of the electrodes.