Physical Properties and Chemical Stability of Polyaniline Layer Prepared by Electro-Polymerization on FTO using Two electrode System
Hanaa Shuker Mahmood and Nadir Fadhil Habubi
In this work, the possibility of using a simple system consisting of two electrodes was studied. Unlike in previous research that used expensive three-electrode systems in preparing nanostructured layers of polyaniline (PANI) with good specifications. PANI films were prepared on fluorine tin oxide slides (FTO) by electrodeposition at a different voltage from an aqueous media of Aniline and sulfuric acid. The structure properties, surface morphology, optical properties, and electrochemical stability for the prepared films at different voltages were characterized. The prepared films appeared uniformly deposited over the dipped part of the FTO with different colours and transparency. The field emission scanning electron microscopy (FESEM) for the prepared samples showed nanostructured and rising deposition voltage cause to increase the diameter of the particles, and the deposition is inhomogeneous. The optical properties investigation shows three broad absorption bands corresponding to the excitation transition of PANI molecular bands in a sample prepared at low voltage. Increasing the voltage causes breaking of the polaron bands and a shift of the bipolaron absorption band from 840 nm to 730 nm. The result of cyclic voltammetry suggested that the nanofilm of PANI has good electrochemical stability where the specific capacitance decreased about 33.63% from its first value after five hundredth cycles of the charge-discharge process.
Keywords: PANI, Electro-polymerization, optical properties, chemical stability