Efficiently improving oxygen evolution activity using hierarchical α-Co(OH)2/polypyrrole/graphene oxide nanosheets

Design and exploit earth-abundant and inexpensive materials as highly active oxygen evolution reaction electrocatalysts for water splitting plays a crucial role for developing renewable energy sources and technologies. Herein, α-Co(OH)2 nanoplates (average thickness of 8–10 nm) are uniformly distributed on polypyrrole/graphene oxide by a very facile method because of coordinating Co2+ with –NH– segments in polypyrrole chains. The electrocatalytic activity towards oxygen evolution reaction can be efficiently improved by α-Co(OH)2/polypyrrole/graphene oxide as electrocatalysts with high activity, strong durability and good stability by the synergies between components and the remarkable hierarchical nanostructures, whose overpotential and Tafel slope can be achieved to 350 mV @ 10 mA cm−2 and 74.5 mV dec−1, respectively. The introduction of polypyrrole not only enhances the nanocomposite conductivity, which effectively facilitates the electronic transmission of oxygen evolution reaction, but also optimizes the uniform distribution of α-Co(OH)2 nanoplates on polypyrrole/graphene oxide, which results in more exposed active sites ascribed to the excellent hierarchical nanostructures. Therefore, conducting polymers as the supports for transition metal compounds can efficiently improve its electrocatalytic performance of oxygen evolution reaction, which will be beneficial to electrocatalytic water splitting.