Conference
Title | Spectrophotometric and Electrochemical Characterization of Phosphoric Acid-Doped Polyaniline Thin Film on ITO as Supercapacitor Electrode Posted by Bryan Montalban |
Authors | Bryan M. Montalban, Mylene M. Uy, and Reynaldo M. Vequizo |
Publication date | 2019 |
Conference | 20th International Union of Materials Research Societies - International Conference in Asia |
Abstract | A highly pseudocapacitive phosphoric acid-doped polyaniline thin film (PA-dPTF) was successfully synthesized and grown on indium tin oxide (ITO) for supercapacitor electrode application. Electropolymerization and deposition of a pseudocapacitive PA-dPTF on ITO was achieved via a facile potentiodynamic technique in a three-electrode electrochemical cell using different anilinium hydrochloride (AnH+) and phosphoric acid (H3PO4) electrolyte concentrations, scanned from 0.2 V to 0.9 V (vs. Ag/AgCl). Spectrophotometric and Electrochemical characterization of the PA-dPTF electrode was investigated using Fourier-transform infrared (FTIR) spectroscopy, optical absorption spectroscopy (OAS), cyclic voltammetry (CV) and galvanostatic charge/discharge (GCD). FTIR analysis of PA-dPTF showed a 47%-51% degree of oxidation indicating an emeraldine salt (ES) form of polyaniline. The observed pi to polaron and polaron to pi* transitions using OAS further confirmed that the thin film was an ES having a HOMO-LUMO gap of 2.36 eV - 2.49 eV an indicative of a semiconducting properties. The electrode material exhibited a high specific capacitance of 314.24ñ17.06 F/g at 0.03 mA/cm2. Repetitive GCD of PA-dPTF electrode for 200 cycles displayed 81% capacitance retention with 90% coulombic efficiency. The electrode afforded a power density of 4.9 kW/kg with an energy density of 50.54 Wh/kg at 0.3 mA/cm2. Finally, Ragone plot showed that the electrochemical performance of the fabricated PA-dPTF lies between the boundary of a supercapacitor and a battery. |
Index terms / Keywords | Electrodeposition, electropolymerization, potentiodynamic, reaction order, apparent rate constant. |