Improved adhesion and charge transfer between PEDOT:PSS and the surface of a platinum electrode through a diazonium chemistry route

Abstract

Due to the high applicability of poly(3,4-ethylenedioxythiophene):poly(4-styrene sulfonate) (PEDOT:PSS) in organic electronics, current research is focused on providing new ways to further improve its functionality. In this paper, we have described a one-step process of electrochemical grafting of commercially available diazonium salts to the surface of a Pt electrode as a method to increase mechanical stability of PEDOT:PSS, simultaneously decreasing its charge transfer resistance and increasing capacitance. Pretreatment of Pt electrodes with electrografted layers of 4-nitrobenzene-, 4-methoxybenzene-, and 3,5-dichlorophenyl diazonium tetrafluoroborates is shown to improve charge storage capacity (235 mC/cm2 at the scan rate of 10 mV/s), decrease charge transfer resistance (15.0 ± 0.5 Ω) and enhance capacitance (13.3 ± 0.8 mF). The described method is also efficient in providing coatings with better affinity to the electrode and higher adhesion force.