Preparation and characterization of poly(3,4-ethylenedioxythiophene)–poly(styrene sulfonate) composite thin films highly loaded with platinum nanoparticles

In this work, we propose a simple and efficient, low-temperature (∼120 °C) process to prepare transparent thin films of poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate) (PEDOT:PSS) loaded with high concentration (up to 22.5 wt%) of platinum (Pt) nanoparticles. Firstly, an improved polyol method was modified to synthesize nano-sized (∼5 nm) and mono-dispersed Pt particles. These nanoparticles were incorporated into the matrix of PEDOT:PSS thin films via a spin coating/drying procedure. The electrochemical activities of the PEDOT:PSS thin film modified electrodes with respect to the I−/I3− redox reactions were investigated. It was found that the modified electrode of PEDOT:PSS thin film containing 22.5 wt% Pt exhibited the electrochemical activity comparable to the conventional Pt thin film electrode, suggesting that this electrode has good potential to serve as a counter electrode in dye-sensitized solar cells.