Haemoglobin/polyindole composites: the novel material for electrochemical supercapacitors

[摘要] Conducting polymers have recently been employed with metal derivative macromolecules that have led to great improvement in the field of supercapacitor materials. The current work reports on the synthesis of a novel class ofhaemoglobin/polyindole composites (HPCs) through doping of haemoglobin (Hb) into a polyindole (PIN) matrix.HPCs with enhanced electrocapacitive performance were prepared through a cationic surfactant-assisted dilute solution polymerization of indole (IN) in the presence of Hb at various concentrations ranging from 10 to 30% (w/w) and ferric chloride (FeCl$_3$) as an oxidant. The HPCs were characterized through Fourier transform infrared spectra, scanning electron microscopy and simultaneous thermogravimetric analysis. Electrochemical capacitance ($C_s$, F g$^{−1}$) of graphite-based electrodes fabricated from HPCs over stainless steel in the presence of sulphonated polysulphone as a binder has been investigated in KOH solution (1.0 M) with reference to Ag/AgCl at a scan rate (V s$^{−1}$) ranging from 0.001 to 0.2. HPCs with 30% (w/w) of Hb have shown the highest Cs of 294.00 as compared with 112.00 for pure PIN at a scan rate of 0.001 V s$^{−1}$. Successivescans of HPC electrodes show a capacitive decline of $\sim$2% during the first 1000 cycles at a scan rate of 0.1 V s$^{−1}$ in KOH (1.0 M), which indicates the appreciable electrochemical cyclic stability of the HPCs over PIN. Thus, the fabricated HPCs may serve as potential electrode material for development of electrochemical supercapacitors.

[学科分类] 材料工程

[关键词] Polyindole;haemoglobin;electrochemical capacitance;supercapacitors.