The Effect of Applied Voltages and Coating Thickness on the Capacitance of Electrode Coated With Poly (Potassium Tetrakis-2-Thienyl Borate)

Abstract

In this study, PT2TB was polymerized electrochemically in 0.1M tetrabutylhexafluorophosphate (Bu4PF6)-Polycarbonate (PC) at range of 0-1.7V and scan rate of 50 mV/s and obtained electrode coated with poly (T-2-TB) was investigated in the way of impedance and capacitance. As a result, it was found that impedance values changed and its capacitive property decreased with increasing of coating thickness. So, specific capacitances (Cspe) were 0.31mF/cm2 and 0.064 mF/cm2 at 2 cycle and 8 cycle, respectively. On the other way, as applied voltage was increased, capacitive feature of polymer was decreased, due to that the structure of polymer was damaged. It was determined that the voltage must be 0V or 0.2V. In morphological investigation, the particles were observed on the polymer surface, which was estimated due to potassium, probably. Nevertheless, cauliflower structure accepted as a typical for Polythiophene was observed on the surface.

Key words: Potassium tetrakis-2-thienyl borate, electropolymerization, electrochemical impedance spectroscopy, capacitance.