Core-shell Fe3O4@CoFe2O4 nanoparticles as high-performance anode catalysts for enhanced oxygen evolution reaction

Water electrolysis is a promising and environmentally friendly means for renewable energy storage. Recent progress in the development of anion exchange membranes (AEMs) has provided new perspectives for high-performance anode catalysts based on transition metal oxides (TMOs) for the sluggish anodic oxygen evolution reaction (OER). Here, we report on core-shell nanoparticles (Fe3O4@CoFe2O4) which allow combining an electrocatalytic shell (CoFe2O4) with a conductive core (Fe3O4). Such an original approach significantly minimizes critical Co content in the catalyst and avoids addition of unstable conductive carbon black. The core-shell nanoparticles outperform Co(1-x)Fe(2+x)O4 nanoparticles and show an exceptional OER activity per Co unit mass (2800 A g(cobalt)(-1) at 1.65 V vs. RHE) suggesting synergistic interaction between the core and the shell. Along with the core-shell structure, the size of the Fe3O4 core is a critical parameter, with a large conductive Fe3O4 core being beneficial for OER enhancement.

Automated summary

Water electrolysis is a promising method for renewable energy storage, and recent advancements in anion exchange membranes have led to the development of high-performance anode catalysts based on transition metal oxides for oxygen evolution reaction. Core-shell nanoparticles combining an electrocatalytic shell with a conductive core have shown exceptional activity for oxygen evolution, suggesting synergistic interaction between the two components. The size of the conductive core also plays a critical role in enhancing the oxygen evolution reaction.