Organics@metals as the Basis for a Silver/Doped-Silver Electrochemical Cell

Classically, an electrochemical cell is constructed from a pair of different metals. Here we demonstrate a new concept: An electrochemical cell in which the two electrodes are made of the same metal. This has been made possible by employing the new methodology of organic doping of metals in the preparation of one of the electrodes. Specifically, pure silver and silver doped with Congo-red (CR) were used. The alteration of the electrode behavior of silver by incorporation of the organic dopant was revealed by potentiometry and cyclic voltammetry: Potentiometry showed that the entrapment of CR inhibits the response of silver to silver ions; voltammetry indicated a 30-fold increase of the reduction current measured at the electrode surface during cathodic sweeps. On the basis of this, we constructed an electrochemical cell in which the potential difference between pure and doped silver electrodes was used to activate a light-emitting diode in an external circuit.