Microcomposite electrochemical capacitor: Electrocoating of poly[N-(hydroxymethyl)carbazole] onto carbon fiber, surface morphology, spectroscopic surface characterization, electrochemical impedance spectroscopy

N-(Hydroxymethyl)carbazole (MeOHCz) was electrocoated on carbon fiber micro electrodes (diameter ∼7 μm) in different solvents by cyclovoltammetric method as thin film (0.17-2.73 μm). Surface characterization of electrocoated poly[N-(hydroxymethyl)carbazole] of carbon fiber microelectrode (CFME) was performed by reflectance FTIR spectroscopy, scanning electron microscopy, and cyclic voltammetry. Capacitor behavior of modified CFME was studied by electrochemical impedance spectrometry. The deposition rate of polymer growth affected the redox parameters of resulting coated CFME. The solvent effect on the redox and capacitor behavior of poly[N-(hydroxymethyl)carbazole] (PMeOHCz)-coated CFME was investigated, and electroactivity in acetonitrile (ACN) was the highest among the investigated solvents. On the other hand, the electrocoated polymer exhibited the faster charge/discharge process in propylene carbonate (PC). PMeOHCz thin film was very stable up to 1000 mV/sin ACN, PC, and dichloromethane (CH₂Cl₂).