Electro-capacitive performance of haemoglobin/polypyrrole composites for high power density electrode

Abstract

Abstract Background Haemoglobin (Hb)-doped polypyrrole (PPy) composites serving as energy storage material have rarely been premeditated. Methods In this perspective, a novel class of haemoglobin/polypyrrole composites (HPyCs) by doping metal derivative Hb into PPy matrix with concentrations (PPy, 1%, 2% and 3% Hb in w/w) has been synthesized by cationic surfactant assisted dilute polymerization method. The obtained samples were exemplified by Fourier transform-infrared spectroscopy (FT-IR) and thermogravimetric-differential thermal analysis-differential thermogravimetry (TG-DTA-DTG). Electrochemical capacitance (Cs, F/g) of electrodes fabricated from PPy and HPyCs over stainless steel in the presence of sulphonated polysulphone as binder has been investigated in KOH solution (1.0 M) with reference to Ag/AgCl at scan rate (V/s) ranging 0.001–0.2. HPyC3% has shown Cs of 445.75F/g along with energy and power densities of 14.37 Wh/kg and 596.54 Wh/kg respectively, which is greater as compared to 200.56F/g for PPy. Conclusion The composites show good charge-discharge with improved electrochemical cyclic stability of the HPyCs over PPy. This behaviour points out that fabricated HPyCs may dole out as prospective electrode materials for development of electrochemical supercapacitors.

Keywords

• Polypyrrole
• Haemoglobin
• Electrochemical capacitance
• Sulphonated polysulphone