Lim, Jeonghyeon Jo, Seunghyun Oh, Hyunjun Choi, Pilsoo Oh, Jungho Seo, Kwangduck Park, Hee-Young Eom, Kwangsup 2025-09-17T02:03:16Z 2025-09-17T02:03:16Z 2025-09-16 2025-10 2050-7488 https://pubs.kist.re.kr/handle/201004/153174 Nickel-iron layered double hydroxide (NiFe-LDH) has attracted considerable attention as an efficient electrocatalyst for the oxygen evolution reaction (OER) in alkaline media. However, the irreversible phase transition from gamma-Ni(Fe)OOH to beta-Ni(Fe)OOH, which is based on the low thermodynamic stability of gamma-Ni(Fe)OOH, results in the poor durability of NiFe-LDH. To address this, this study designs an NiFe-LDH/NiB heterostructure (NiFe@NiB). Because NiB acts as an electron acceptor, it modulates the Ni oxidation state (Ni3+ -> Ni(3+delta)+) and facilitates the beta-to-gamma phase optimization. Notably, NiFe@NiB maintains a higher gamma-phase fraction during OER cycling and exhibits an expanded 2D layered structure, which is a structural feature of the active gamma-phase. In conclusion, NiFe@NiB requires 75 mV lower overpotential to achieve 10 mA cm-2 and one-fifth degradation rate with 93.2% reduced Fe leaching over 120 hours of durability test compared to NiFe-LDH. This work presents a compelling strategy for designing efficient and durable electrocatalysts for sustainable hydrogen production. English Royal Society of Chemistry A phase-optimized NiFe-LDH/NiB heterostructure as an efficient and durable oxygen evolution electrocatalyst in alkaline media Article 10.1039/d5ta04549e 1 Journal of Materials Chemistry A, v.13, no.39, pp.33479 - 33489 Journal of Materials Chemistry A 13 39 33479 33489 N scie scopus 001562824000001 Chemistry, Physical Energy & Fuels Materials Science, Multidisciplinary Chemistry Energy & Fuels Materials Science Article DOUBLE HYDROXIDE OXIDATION CATALYSTS HYDROGEN FUTURE FUEL