Two-Dimensional Heterostructure of PPy/CNT- E. coli for High-Performance Supercapacitor Electrodes.

The nano-biocomposite electrodes composed of carbon nanotube (CNT), polypyrrole (PPy), and E. coli -bacteria were investigated for electrochemical supercapacitors. For this purpose, PPy/CNT- E. coli was successfully synthesized through oxidative polymerization. The PPy/CNT- E. coli electrode exhibited a high specific capacitance of 173 F∙g -1 at the current density of 0.2 A∙g -1 , which is much higher than that (37 F∙g -1 ) of CNT. Furthermore, it displayed sufficient stability after 1000 charge/discharge cycles. The CNT, PPy/CNT, and PPy/CNT- E. coli composites were characterized by x-ray diffraction, scanning electron microscopy, and surface analyzer (Brunauer-Emmett-Teller, BET). In particular, the pyrrole monomers were easily adsorbed and polymerized on the surface of CNT materials, as well as E. coli bacteria enhanced the surface area and porous structure of the PPy/CNT- E. coli composite electrode resulting in high performance of devices.