Enhanced electrochemical performance by polyaniline (PANI) on covalent organic framework - Carbon nanotube (COF-CNT) as cathode catalyst for microbial fuel cells

Abstract

Electrochemical catalysts based on polyaniline derived covalent organic framework-carbon nanotube composite (PANI@COF-CNT) was successfully fabricated by chemical oxidation polymerization method. Rougher surface morphologies of PANI@COF-CNT was obtained attributing to PANI loading with the porous framework, forming a unique well-distributed network structure. The specific surface area and pore diameter of PANI@COF-CNT were 99.533 m2/g and 24.916 nm, which were 13.220 and 1.913 times of that of PANI@COF. The output voltage of PANI@COF-CNT MFC could be stably sustained at about 0.390 V with no significant change after 120 h. The maximum power density of PANI@COF-CNT MFC was 194.480 mW/m2, which was 8.655 folds higher than that of the pristine COF cathode MFC. The coral bone-like structure of COF and the porous structure of CNT provided abundant electroactive sites, and the high conductivity of PANI significantly enhanced the electron transfer rate and effectively reduced the transport resistance, which in turn effectively strengthened the electrochemical performance and cycling stability of MFC.