College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China.
School of Chemical Biology and Materials Engineering, Suzhou University of Science and Technology, Suzhou 215009, P. R. China.
Inorg Chem. 2023 Feb 20;62(7):3238-3247. doi: 10.1021/acs.inorgchem.2c04261. Epub 2023 Feb 9.
Metal-organic framework (MOF) has become a popular electrocatalyst for the oxygen evolution reaction (OER) because of its large specific surface area and adjustable porosity. Nevertheless, the electrochemical performance of MOFs has been greatly limited by poor intrinsic conductivity and catalytic activity. Herein, we report a Ce-doped nanoflower-like MOF material Ce@NiFe-MOF-5 via a facile ion competitive coordination effect and doping method. Benefiting from the nanoflower structure formed by the stacking of nanosheets, a large number of active sites can be exposed, which favors electron/mass transfer during water oxidation. The coordination substitution of Ce ions not only promoted an increase in the number of active sites on the surface of the nanosheets but also optimized the electronic structure of pristine NiFe-MOF. The well-designed Ce@NiFe-MOF-5 catalysts exhibited superior OER performance under basic conditions, which only required an overpotential of 258 mV at a current density of 10 mA cm and a Tafel slope of 54.44 mV dec. Moreover, when Ce@NiFe-MOF-5 served as an anode and Pt/C as a cathode, the two-electrode system only needed 1.56 V to drive overall water splitting at 10 mA cm.
金属-有机骨架（MOF）因其具有较大的比表面积和可调节的孔隙率而成为一种很受欢迎的析氧反应（OER）电催化剂。然而，MOFs 的电化学性能受到较差的本征电导率和催化活性的极大限制。在此，我们通过简便的离子竞争配位效应和掺杂方法，报道了一种 Ce 掺杂的类纳米花 MOF 材料 Ce@NiFe-MOF-5。得益于纳米片堆积形成的纳米花结构，可以暴露大量的活性位点，有利于水氧化过程中的电子/质量传递。Ce 离子的配位取代不仅促进了纳米片表面活性位点数量的增加，而且优化了原始 NiFe-MOF 的电子结构。设计良好的 Ce@NiFe-MOF-5 催化剂在碱性条件下表现出优异的 OER 性能，在电流密度为 10 mA cm 时仅需要 258 mV 的过电位和 54.44 mV dec 的塔菲尔斜率。此外，当 Ce@NiFe-MOF-5 用作阳极，Pt/C 用作阴极时，该两电极系统仅需 1.56 V 即可在 10 mA cm 下驱动整体水分解。
