Take a cue from nature: Promoting electrocatalytic watersplitting with a helping hand of hemoglobin

Abstract Electrocatalytic water splitting is a promising approach to generating hydrogen from water. In order to enhance water splitting efficiency, it is essential to promote gas revolution from catalysts surface, reduce the over-potential of oxygen evolution (OER), and inhibit the production of the hydrogen peroxide by-product. To realize them, in this work, we take a cue from nature to promote water splitting activity of hollow porous Fe3O4 microspheres (M−Fe3O4) with the aids of hemoglobin. Hemoglobin monolayer was self-assembled on the surface of M−Fe3O4 catalysts. It transported newly-generated oxygen molecules away from catalysts surface and exhibited chiral-induced spin selectivity (CISS) effect during OER reaction. Owing to the “helping hand” of hemoglobin, the OER onset potential of hollow porous Fe3O4 microspheres reduced by 100 mV and the current density was enhanced 2 folds. The results indicate a new strategy for designing earth-abundant catalysts which combine the merits of oxygen transferring and CISS effect for electrocatalytic water splitting.