Electropolymerization Polyoxometalate (POM)-Doped PEDOT Film Electrodes with Mastoid Microstructure and Its Application in Dye-Sensitized Solar Cells (DSSCs)

A polyoxometalate (POM)-doped poly(3,4-ethylenedioxythiophene) (PEDOT) hybrid film counter electrode was successfully fabricated by electropolymerization in an environmentally friendly aqueous solution. The hybrid film presents a similar surface morphology to lotus leaf, the microstructure of which is a regularly distribution of mastoid shapes. As far as we know, it is the first time that POM-PEDOT hybrid film with mastoid morphology was fabricated. The application of the hybrid film counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) was studied for the first time, and the efficiency of DSSCs based on hybrid film CEs was almost as high as DSSCs with Pt CEs. FTIR results indicated that POM polyanions had already been dispersed into the PEDOT matrix. Cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel polarization test results show that the electrocatalytic ability for I-3(-) reduction of the hybrid film CE is comparable to that of a Pt CE. In addition, the SiWII-PEDOT hybrid film has good electrochemical stability.