Hu Yitian, Fan Yalei, Li Lili, Zhou Jing, Hu Zhiwei, Wang Jian-Qiang, Dong Juncai, Zhao Shenlong, Zhang Linjuan
Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China.
Department of Environmental and Chemical Engineering, Nanchang Hangkong University, Nanchang, 330063, China.
Small. 2024 Aug;20(34):e2400042. doi: 10.1002/smll.202400042. Epub 2024 Apr 11.
Modulating the coordination environment of the metal active center is an effective method to boost the catalytic performances of metal-organic frameworks (MOFs) for oxygen evolution reaction (OER). However, little attention has been paid to the halogen effects on the ligands engineering. Herein, a series of MOFs X─FeNi-MOFs (X = Br, Cl, and F) is constructed with different coordination microenvironments to optimize OER activity. Theoretical calculations reveal that with the increase in electronegativity of halogen ions in terephthalic acid molecular (TPA), the Bader charge of Ni atoms gets larger and the Ni-3d band center and O-2p bands move closer to the Fermi level. This indicates that an increase in ligand negativity of halogen ions in TPA can promote the adsorption ability of catalytic sites to oxygen-containing intermediates and reduce the activation barrier for OER. Experimental also demonstrates that F─FeNi-MOFs exhibit the highest catalytic activity with an ultralow overpotential of 218 mV at 10 mA cm, outperforming most otate-of-the-art Fe/Co/Ni-based MOFs catalysts, and the enhanced mass activity by seven times compared with that for the sample before ligands engineering. This work opens a new avenue for the realization of the modulation of NiFe─O bonding by halogen ion in TPA and improves the OER performance of MOFs.
调节金属活性中心的配位环境是提高金属有机框架材料（MOFs）析氧反应（OER）催化性能的有效方法。然而，卤素对配体工程的影响却很少受到关注。在此，通过构建一系列具有不同配位微环境的MOFs（X─FeNi-MOFs，X = Br、Cl和F）来优化OER活性。理论计算表明，随着对苯二甲酸分子（TPA）中卤素离子电负性的增加，Ni原子的巴德电荷增大，Ni-3d带中心和O-2p带向费米能级靠近。这表明TPA中卤素离子配体负性的增加可促进催化位点对含氧中间体的吸附能力，并降低OER的活化能垒。实验还表明，F─FeNi-MOFs表现出最高的催化活性，在10 mA cm时过电位低至218 mV，优于大多数最先进的Fe/Co/Ni基MOFs催化剂，与配体工程前的样品相比，质量活性提高了7倍。这项工作为通过TPA中的卤素离子实现NiFe─O键的调控开辟了一条新途径，并提高了MOFs的OER性能。
