A bio-inspired 3D quasi-fractal nanostructure for an improved oxygen evolution reaction.

We demonstrate a bio-inspired three-dimensional (3D) hierarchical catalyst, based on the Fe-doped nanoarrays of dendritic nickel trees, which provides large surface area, close to optimal electron transport, and large inter-branch open-channels for improving gas-bubble release, outperforming the benchmark catalyst of noble RuO2.