Kim, Byeongyoon Kabiraz, Mrinal Kanti Lee, Jaewan Choi, Changhyeok Baik, Hionsuck Jung, Yousung Oh, Hyung-Suk Choi, Sang-Il Lee, Kwangyeol 2024-01-19T13:31:51Z 2024-01-19T13:31:51Z 2022-01-10 2021-11 2590-2393 https://pubs.kist.re.kr/handle/201004/116203 The layered transition metal oxyhydroxides have received increasing interest owing to the efficient energy conversion performance and material stability during the oxygen evolution reaction (OER). In particular, Fe-doped NiOOH has shown record-high OER performance in alkaline media among various catalysts. Theoretically, undercoordinated facets including Ni4+, exposed at the edges of NiOOH, were predicted to perform highly active OER. Therefore, here we suggest a rational catalyst design, a vertical-crystalline beta-Fe/NiOOH layer built on faceted Fe/Ni nanocrystals, which exposes Ni4+ sites and could improve the OER performance dramatically. Electrochemical OER tests recorded the overpotential of 210 mV at a current density of 10 mA cm(-2) GEO and stable operation for 5 days. In situ/operando and density functional theory studies revealed that the Ni valence cycle between +2 and +4 assisted by Fe dopant is the key engine that greatly accelerates OER kinetics and that the vertical-crystalline beta-Fe/NiOOH layers on Ni octahedra are stable under harsh OER conditions. English Cell Press Vertical-crystalline Fe-doped beta-Ni oxyhydroxides for highly active and stable evolution reaction Article 10.1016/j.matt.2021.09.003 1 Matter, v.4, no.11, pp.3585 - 3604 Matter 4 11 3585 3604 N scie scopus 000717520800003 2-s2.0-85123000978 Materials Science, Multidisciplinary Materials Science Article MEMBRANE WATER ELECTROLYSIS OXYGEN-EVOLUTION ELECTRONIC-STRUCTURE REACTION DYNAMICS REDOX STATES CATALYSTS ELECTROCATALYSTS OXIDE OXIDATION XANES Heteroepitaxy Oxygen evolution reaction Crystalline Fe/NiOOH AEMWE Facet control