Oxyanions Enhancing Crystallinity of Reconstructed Phase for Oxygen Evolution Reaction

The catalysts were always undergoing continuous amorphization and dissolution of active structure in operating condition, hindering the compatibility between stability and activity for oxygen evolution reaction (OER). Herein, we propose the selective adsorption of leached NO3− to strengthen the crystallinity and activity of surface reconstructed layer with amorphous and crystalline (a‐c) heterojunction. Taking a‐c Ni doped Fe2O(OH)3NO3 ⋅ H2O (Ni−FeNH) as a model precatalyst, we uncover that the leached NO3− are readily adsorbs on the crystalline phase in the formed a‐c Fe(Ni)OOHduring OER, lowering the disorder degree and further activating Ni and Fe ion of the crystalline Fe(Ni)OOH on a‐c heterojunctions. Accordingly, Ni−FeNH deliver a low overpotential of 303 mV and high durability of 500 hours at 500 mA cm−2 for OER. Particularly, constructing industrial water electrolysis equipment exhibits high stability of 100 hours under a high operating current of 8000 mA. A hetero oxyanion was proposed to enhance the crystallinity and activity of reconstructed phase in operation. Taking an amorphous and crystalline (a‐c) heterojunction of Ni doped Fe2O(OH)3NO3 ⋅ H2O as model, in situ NO3− leaching and reabsorbing lower the disorder degree and activate Fe (Ni) ion of renewed a‐c heterojunctions, achieving the compatibility of activity and stability for OER.