Defect-rich Fe-doped CeO2 nanosheets as effective oxygen evolution electrocatalysts

Designing nanocatalysts with defect architectures and heteroatom doping can increase the performance of the electrocatalyst used for OER. With the assistance of microwave strategy, we synthesized two-dimensional (2D) Fe-doped CeO2 nano-sheets (Fe/CeO2 NSs) containing oxygen vacancies (Ov) for oxygen evolution reaction (OER) electrocatalyst by calcining Fe-doped Ce(C2O4)3 as precursor at different temperatures. Benefiting from lattice defects derived from Ov and doped Fe, the electrocatalysis of Fe/CeO2-400 NSs shows a much smaller Tafel slope of 46 mV·decade-1 than that of pure CeO2. Furthermore, the polarization curves only slightly changed after 1000 cyclic voltammetry (CV) cycles which also confirmed the good stability of the Fe/CeO2-400 NSs. The outstanding electrocatalytic properties as well as the stability of Fe/CeO2 NSs should be attributed to the active sites contributed by the defective regions on the nanosheets, while Fe is doped into the CeO2 lattice as a heteroatom and affects the electronic structure, improving the overall OER performance.