Co-Prussian blue analogue supported on graphene-based materials as an electrocatalyst for OER at neutral pH

Abstract

The development of efficient, robust, and low-cost electrocatalysts for the oxygen evolution reaction (OER) under mild conditions is a sustainable pathway for energy conversion and storage technologies. Cobalt Prussian blue analogue (Co-PBA) has been emerging as a potential candidate to be engineered and match such requirements. In this study, the catalytic activity performance of Co-PBA was improved by depositing over different types of graphene-based materials that act as supports, resulting in hybrid composites. The Co-PBA + r_GO N2, which is Co-PBA deposited over a reduced graphene oxide doped with N atoms (urea as N source), showed the best OER catalytic improvements in a neutral medium (0.5 mol L⁻¹ KNO₃), reducing the overpotential in 54 mV and 137 mV to reach current densities of 10 (J₁₀) and 50 (J₅₀) mA cm⁻², respectively, in comparison to the sole electrocatalyst Co-PBA. These results indicate that the interaction between the Co-PBA and graphene-based supports plays a pivotal role in effectively enhancing the OER activity of the electrocatalyst.