Strategic Defect Engineering Enabled Efficient Oxygen Evolution Reaction in Reconstructed Metal‐Organic Frameworks

• Published in: Advanced functional materials Vol. 35; no. 4
• Main Authors: Zhang, Yin‐Qiang, Liu, Ming, Zhang, Le‐Tian, Lu, Nan, Wang, Xuemin, Li, Zhi‐Gang, Zhang, Xing‐Hao, Li, Na, Bu, Xian‐He
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.01.2025
• Subjects: Carboxylic acids; Catalytic activity; Defects; Density functional theory; Density functions; Doping; Iron; Metal foams; Metal-organic frameworks; Nickel; oxygen evolution reaction; Oxygen evolution reactions; oxygen vacancy; Reconstruction; structural reconstruction
• DOI: 10.1002/adfm.202412406
• ISSN: 1616-301X

Metal‐organic frameworks (MOFs) have emerged as promising pre‐catalysts for oxygen evolution reaction (OER) due to their marvelous structural reconstruction process in strongly alkaline media. However, targeting design MOF structures to achieve excellent OER performance of reconstructed products is a challenge. Here, a strategic defect engineering is used to promote the OER performance of reconstructed products. Briefly, modified linkers with monocarboxylic acids (ferrocene carboxylic acid, FcCA) are incorporated into MOF (NiBDC‐FcCA), leading to its stepwise reconstruction into Fe‐doped Ni(OH)2 and NiOOH during the OER process, with the oxygen vacancy and strategic doping of metal Fe persisting throughout the multi‐step reconstruction. Benefiting from the synergistic interaction of oxygen vacancies and Fe doping, NiBDC‐FcCA delivers the extremely enhanced current density at 1.6 V versus reversible hydrogen electrode by ≈9 times compared with that of NiBDC. Moreover, the optimized NiBDC‐FcCA/Fe foam exhibits excellent OER catalytic activity and stability with a low overpotential of 250 mV at 200 mA cm−2 and negligible activity decay after 1200 h at 1 A cm−2. Density function theory calculations reveal that Fe doping weakens the interaction of oxygen intermediate with Ni sites, favoring the formation of OOH* to accelerate the OER process. Herein, a strategic defect engineering is proposed to obtain the expected reconstructed products that inherit the nature of the pre‐catalyst MOF, namely, the oxygen vacancy and strategic doping of metal Fe persisting throughout the multi‐step reconstruction. The electron structure and adsorption energy of the reconstructed products are adjusted, thus delivering excellent oxygen evolution reaction performance.