Ce-doped nanorod-like NiFe-MOF with coordination substitution based on in situ codoping method for boosting the oxygen evolution reaction.

Heteroatom-doped metal--organic frameworks (MOFs) have been widely used in OER catalysis. However, the effects of doping methods on these materials have rarely been reported. Herein, the structure and activity of Ce-doped nanorod-like MOFs (CeNi_1.6Fe-MIL-53 and Ce@Ni_1.6Fe-MIL-53) prepared by employing in situ co-doping and surface doping methods were analyzed. The structure of Ni_1.6Fe-MIL-53 can be optimized at different levels by different Ce-introduction ways. In contrast, the in situ codoping of Ce increases the number of active sites and better optimizes the band structure. Therefore, CeNi_1.6Fe-MIL-53 exhibited good OER activity, which required an overpotential of only 277 mV at a current density of 10 mA cm^-2, a Tafel slope of 31.03 mV dec^-1 and a good stability maintained for 60 h. Moreover, when CeNi_1.6Fe-MIL-53 was coupled as an electrolytic cell, the cell showed a low cell potential (1.54 V at 10 mA cm^-2) and good stability (maintained for 33 h). [ABSTRACT FROM AUTHOR]