Composition-Balanced Bi-Metallic MOFs Directly Grown on Nickel Foam for High-Efficiency Oxygen Evolution Reaction
Shangkun Deng, Ziliang Li, Kang Xu, Zhu Liu, Zhuangzhuang Yin, Hai Yu, Jianguo Lv, Lei Yang, Zhaoqi Sun, Miao Zhang
Abstract
In this paper, the electrocatalytic efficiency of bi-metallic organic framework compounds grown on nickel foam (NF) has been enhanced by adjusting the amount of iron and cobalt precursors. A unique wedge-like morphology was observed in Fe-1-Co-1-MOF. The optimized Fe-1-Co-1-MOF (1:1 of molar ratio of iron to cobalt) exhibits superior catalytic activity to oxygen evolution reaction (OER) performance with a lowest overpotential of only 233 mV at a current density of 10 mA·cm −2 and the higher current density of 400 mA·cm −2 can be provided at overpotential of 264 mV. The Tafel slope in alkaline aqueous solutions was 24.4 mV·dec −1 . After 10 h of continuous operation, the catalyst showed only a slight loss of current density at 50 mA·cm −2 . This success may be attributed to synergy between the bi-metallic organic framework catalyst and the large pores of conductive nickel foam, as well as the synergistic effect between the two phases molecules of the bi-metallic organic framework metal.