Boosting activity on CoFe layered double hydroxide by doping and heterostructure as a bifunctional electrocatalyst for efficient overall water splitting

Abstract

The development of economically feasible and efficient bifunctional electrocatalysts for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in electrochemical water splitting for hydrogen generation is highly significant. Here, the OER and HER activities on CoFe LDH are enhanced by coupling CeCO3OH to construct heterostructures and doping Ce atoms. The results reveal strong electronic interactions at the heterointerface, leading to the generation of abundant oxygen vacancies (OVs). Ce doping induces lattice distortion in CoFe LDH leading to a large number of defects and simultaneously leading to changes in the morphology of the layer. Benefiting from their synergistic effects, the prepared CeCO3OH/Ce-CoFe LDH heterostructure exhibits excellent OER and HER performance with low overpotentials of 216 mV and 165 mV at 10 mA cm−2 respectively in alkaline media. Moreover, it demonstrates robust stability (OER: 94 h at 100 mA cm−2) in 1.0 M KOH electrolyte. When employed as both the anode and cathode catalyst, it demonstrates good stability for 77 h. This work provides a new perspective on the design of LDH-based bifunctional catalysts for overall water splitting.