Reagents and materials
Tetrabutylammonium tetraflouroborate(TBATFB), Sulfuric acid (A.C.S. Reagent), and catechol ( certified were obtained from Fischer Scientific. Acetonitrile (HPLC grade, Aldrich) was used as solvent for electrochemical polymerization and, 2,2 - bithiophene monomers were obtained from Aldrich. The monomers were stored at 00 C, 0.1 M Sulfuric Acid, (ACS Reagent, Fisher), was used as electrolyte in cyclic voltammetric studies. Deionized water was from Barnsted. All solutions were freshly prepared before each polymerization.
Electropolymerization conditions and apparatus
The electropolymerization of the 0.05M 2,2-bithiophene monomer solution diluted with 0.1 M TBATFB in acetonitrile at a polished Pt electrode (1.6mm) were carried out in a one compartment cell containing three electrodes, (as illustrated in Figure 1): working, reference and auxillary. Platinum wire was the auxillary electrode and the reference electrode was Ag/AgCl/3M NaCl (MF-2074, BAS) used in the three-electrode compartment cell. Various constant potentials of +1.8V, +1.7V, +1.6V or +1.5V were applied for 10 seconds using a CH 650B potentiostat-galvanostat (CH Instruments Inc.). Surface and spectral examination was performed using a JEOL 35 scanning electron microscope.
The electrolyte solutions of 0.1 M TBATFB dissolved in acetonitrile were deaerated with argon for ten minutes. After the electropolymerization, the PBTP electrode was rinsed with deionized water. A scan rate of 50mV s-1 was used through out the studies.
Figure 1. Schematic diagram of three-electrode compartment single compartment cell.