ScholarWorks@중앙대학교

초록

Heterointerface engineering is an effective strategy to enhance electrocatalytic activity for water splitting by binding two different materials. Specifically, it offers prospects in creating viable transition-metal-based anode materials for catalyzing the oxygen evolution reaction (OER). However, despite its promise, metal/metal oxide heterointerface engineering has not been comprehensively explored for maximizing the electrocatalytic performance, that is, for minimizing the OER overpotential and maintaining the physicochemical characteristics of the catalyst during operation. Therefore, to resolve these issues, the present study was aimed at synthesizing colloidal nanoparticles (NPs) in mixed form at various Ni/Fe ratios (100 : 0 to 0 : 100) to create heterointerfaces between metallic Ni and Fe2O3 NPs. Among the prepared NPs, the 75 : 25 sample annealed under H2/Ar atmosphere recorded the highest alkaline water oxidation activity (199 mV at 10 mA cm-2) with long-term durability for five days, indicating that the 75 : 25 ratio was the optimal composition for generating abundant Ni/Fe2O3 heterointerfaces. The practical applicability of the 75 : 25 sample was confirmed by its remarkable performance as an anode catalyst for an anion exchange membrane water electrolyzer (AEMWE). The outstanding electrocatalytic performance of the 75 : 25 specimen was induced not only by the interparticle interactions between Ni and Fe2O3 NPs, but also by the intraparticle interactions within the heterostructured NPs. Overall, this report illustrates the benefits of Ni/Fe2O3 heterointerface engineering in obtaining highly efficient anode catalysts for AEMWEs.

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