Synthesis, characterization, and electrochemical properties of polyaniline/Co(II) metal-organic framework composites

Polyaniline/Co(II) metal-organic framework composites (PANI/x%Co-MOF) were synthesized by hydrothermal preparation of Co(II) metal-organic framework in the presence of as-prepared polyaniline. The composites were characterized using powder X-ray diffraction (PXRD), fourier-transform infrared (FT-IR), scanning electron microscopy (SEM), and Co elemental EDS-mapping. Crystal stability of Co(II) metal-organic framework in the composites was confirmed by powder X-ray diffraction. The Co elemental EDS-mapping shows that the cobalt is uniformly dispersed in the polymer matrix. Electrochemical properties of prepared composites were evaluated by cyclic voltammetry (CV) and galvanostatic charge/discharge methods in a conventional three-electrode system. The results of electrochemical studies showed that the PANI/50%Co-MOF composite has the highest specific capacitance, 144 F g-1, at 1 A g-1 current density in KNO3 (3 M) electrolyte. The composite electrodes have shown a higher capacity than pure polyaniline and Co(II) metal-organic framework, due to the synergistic effects.