Three-dimension structural Co-Fe-P/Cu3P derived from the Prussian blue analogue (PBA) grown on nanorods for oxygen evolution reaction

Rational design of non-noble metal electrocatalyst with high stability and activity for OER is desirable for the production of renewable energy to solve the environmental crisis. Starting from Prussian blue analogues (PBAs) with special advantages, the trimetallic hollow structural Co-Fe-P/Cu3P/CF covered with extended nanosheets grown on nanorods was synthesized via ion exchange and calcination approaches in this study. The overpotential of the prepared electrode was only 205 mV at a current density of 100 mA/cm2, and it can maintain the stable catalytic activity for at least 60 h. The prominent electric performance is mainly attributed to the construction of the unique morphology, in which the rod-shaped structure can promote the transportation of the reactants, and the hollow structure as well as the nanosheets outside can expand the specific surface area. The electronic interaction between multiple metals can also improve the conductivity of the catalyst. The characterization analysis of the post electrode after long-term oxygen evolution reaction imply that the surface of the catalytic electrode was partially oxidized to the corresponding oxide, which can generate the new active sites to maintain the high catalytic activity together with the residual phosphide. Our research might provide a new reference for the deep exploration of PBA-based materials applied in electrochemical energy conversion and storage.