Carbon-Coated CeO2-CoFe Core-Shell electrocatalysts derived from Prussian blue analogues for high-performance oxygen evolution reactions

In this study, we synthesized a core–shell electrocatalyst (NC@CeO₂-CoFe) composed of CeO₂ anchored onto CoFe Prussian blue analogue (CoFe PBA) nanocubes, which were coated with polydopamine (PDA) and subsequently carbonized into a nitrogen-doped carbon shell. The synergistic interaction between CeO₂ and CoFe PBA enhances electron transfer, increases oxygen vacancy density, and optimizes the electronic structure, resulting in superior oxygen evolution reaction (OER) performance. Furthermore, the PDA-derived carbon shell boosts electrical conductivity and prevents framework collapse or metal leaching during extended electrochemical operation. Owing to these features, NC@CeO₂-CoFe achieves a low overpotential of 255 mV at 10 mA·cm⁻² and exhibits a Tafel slope of 47 mV·dec^–1, indicative of rapid reaction kinetics. Additionally, the NC@CeO₂-CoFe catalyst demonstrates remarkable durability, sustaining stable performance for over 1,000 h at both 10 and 100 mA·cm⁻² in an alkaline medium. This work highlights the potential of NC@CeO₂-CoFe as a robust OER catalyst for sustainable hydrogen production via water electrolysis, addressing key challenges in stability, efficiency, and cost-effectiveness. Insights from this study pave the way for advanced core–shell catalysts in renewable energy applications, presenting a promising approach toward scalable, sustainable hydrogen generation.