Bioinspired Engineering of Cobalt-Phosphonate Nanosheets for Robust Hydrogen Evolution Reaction

The conversion of water to hydrogen (hydrogen evolution reaction, HER) in regenerative fuel cells promises an environmentally friendly framework for smoothing out the energy crisis. However, addressing this issue depends on the development of efficient electrocatalyst design to replace precious platinum catalysts. Herein, we construct cobalt-phosphonate coordination polymer nanosheets bioinspired by active center engineering and coordination environments of catalytic sites in natural enzymes, which catalyze HER at an overpotential of 84 mV under neutral conditions. We propose that the introduction of a phosphate group tunes the electron density of the cobalt ion center and synergistically accelerates HER in a bifunctional activation mechanism of water molecules. This research sheds light on the relationship between the electrocatalyst structures and their catalytic activities, a concept that has broad implications for the design of efficient electrocatalysts in energy conversion.