Synthesis of multi-walled carbon nanotube/polypyrrole nanocomposites by in situ polymerization method and investigation of their supercapacitor properties

PPy and MWCNT/PPy nanocomposites were synthesized by chemical oxidative polymerization method and the supercapacitor properties of the obtained nanocomposites were investigated. In addition, pristine MWCNT was functionalized with 3:1 ratio of acid (H2SO4/H2O2) and base (NH4OH/H2O2) solutions and a-MWCNT/d-PPy and b-MWCNT/d-PPy nanocomposites were obtained. Homogeneous distribution of MWCNTs in polypyrrole matrix and shell-core type morphological structures of nanocomposites was observed by SEM images. It has been observed by SEM, FTIR and XRD analyzes that the functional groups formed by the functionalization of MWCNTs cause the MWCNTs to come together and partially agglomerate. The conductivity of nanocomposites composed of MWCNT and d-PPy was found to be higher than that of pure d-PPy. CV, GCD and EIS results show that the use of a-MWCNT and b-MWCNTs in nanocomposites with low particle content positively affects the supercapacitor properties of the materials, but negatively at high particle contents. It has been observed that the aggregated functional MWCNT particles in nanocomposites with high particle content cause a decrease in the conductivity and dispersion of ions in the electrodes, and thus a decrease in their energy storage capacity.