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Free keywords:
amorphous, local structure, NiFe, oxygen evolution reaction, perovskites
Abstract:
Rationally designing active and durable catalysts for the oxygen evolution reaction (OER) is of primary importance in water splitting. Perovskite oxides (ABO 3 ) with versatile structures and multiple physicochemical properties have triggered considerable interest in the OER. The leaching of A site cations can create nanostructures and amorphous motifs on the perovskite matrix, thus facilitating the OER process. However, selectively dissolving A site cations and simultaneously obtaining more active amorphous motifs derived from the B site cations remains a great challenge. Herein, a top-down strategy is proposed to transform bulk crystalline perovskite (LaNiO 3 ) into a nanostructured amorphous hydroxide by FeCl 3 post-treatment, resulting in an extremely low overpotential of 189 mV at 10 mA cm −2 . The top-down-constructed amorphous catalyst with a large surface area has dual NiFe active sites, where high-valence Ni 3+ -based edge-sharing octahedral frameworks are surrounded by interstitial distorted Fe octahedra and contribute to the superior OER performance. This top-down strategy provides a valid way to design novel perovskite-derived catalysts. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
