Ce-Modified Flowerlike NiFe-MOF Nanostructure Based on Ion Competitive Coordination for Enhancing the Oxygen Evolution Reaction
Xiao Wei1, Dongmei Liu1, Cheng Wang1, Rui Yu1, Kewang Zhang1, Shujin Li1,*（李淑瑾）, Zhengying Wu2,*（吴正颖）, and Yukou Du1,2,*（杜玉扣）
1 College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
2 School of Chemical Biology and Materials Engineering, Suzhou University of Science and Technology, Suzhou 215009, P. R. China
3 School of Optical and Electronic Information, Suzhou City University, Suzhou 215104, P. R. China
Inorg. Chem. 2023, 62, 3238--3247
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–2 and a Tafel slope of 54.44 mV dec–1. 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–2.