Amorphous NiFe Oxide‐based Nanoreactors for Efficient Electrocatalytic Water Oxidation. (2nd March 2023) - Li, Xiaojie
Abstract: Synergy engineering is an important way to enhance the kinetic activity of oxygen‐evolution‐reaction (OER) electrocatalysts. Here, we fabricated NiFe amorphous nanoreactor (NiFe‐ANR) oxide as OER electrocatalysts via a mild self‐catalytic reaction. Firstly, the amorphousness helps transform NiFe‐ANR into highly active hydroxyhydroxides, and its many fine‐grain boundaries increase active sites. More importantly, as proved by experiments and finite element analysis, the nanoreactor structure alters the spatial curvature and the mass transfer over the catalyst, thereby enriching OH − in the catalyst surface and inner part. Thus, the catalyst with the structure of amorphous nanoreactors gained excellent activity, far superior to the NiFe catalyst with the structure of crystalline nanoreactor or amorphous non‐nanoreactor. This work provides new insights into the applications and mechanisms of amorphousness and nanoreactors, embodying the "1+1>2" synergy of crystalline state and morphology. Abstract : Amorphous NiFe oxide‐based nanoreactors were synthesized and applied as water oxidation electrocatalysts. The nanoreactor structure changes the catalyst′s spatial curvature and mass transfer, enriching OH − on the catalyst surface and inside the channels, so that a high current density is obtained. In addition, the combination of amorphousness and nanoreactors synergistically promotes oxygen evolution, achieving the effect of "1+1>2".