Conducting-Polymer Nanocomposites as Synergistic Supports That Accelerate Electro-Catalysis: PEDOT/Nano Co₃O₄/rGO as a Photo Catalyst of Oxygen Production from Water

Abstract

This work describes how conducting polymer nanocomposites can be employed as synergistic supports that significantly accelerate the rate of electro-catalysis. The nanocomposite PEDOT/nano-Co3O4/rGO is discussed as an example in this respect, which is specific for photo electro-catalytic oxygen (O2) generation from water using light (PEDOT = poly (3,4-ethylenedioxythiophene); rGO = reduced graphene oxide). We show that the conducting polymer PEDOT and the conductive additive rGO may be used to notably amplify the rate of O2-generation from water by the nano catalyst, Co3O4. A composite film containing the precise molar ratio 7.18 (C; PEDOT):1 (Co):5.18 (C; rGO) exhibited high photocatalytic activity (pH 12) for the oxygen evolution reaction (OER) at 0.80 V (vs. Ag/AgCl), with a current density of 1000 ± 50 μA/cm2 (including a photocurrent of 500 μA/cm2), achieved after >42 h of operation under illumination with a light of intensity 0.25 sun. By comparison, the best industrial catalyst, Pt, yielded a much lower 150 μA/cm2 under the same conditions. Oxygen gas was the sole product of the reaction.

Keywords

• conducting polymer
• reduced graphene oxide
• photocatalysis
• water-splitting
• nanocomposite