Amorphous hetero-structure iron/cobalt oxyhydroxide with atomic dispersed palladium for oxygen evolution reaction

The activity of iron oxyhydroxides (FeOOH) in oxygen evolution reaction (OER) is limited by its poor conductivity and the high energy barrier in the rate-determining step. Herein, we report the immobilization of atomic dispersed Pd species on Co doped FeOOH, realizing the preparation of amorphous hetero-structure FeCoaOOH-Pdb. In the case of Co/Fe of 0.68 and Pd/Fe of 0.026, the coexisting structure of nanorods and nanospheres with appropriate oxygen vacancies and unsaturated active centers increases the number of active sites and enhances the intrinsic activity of the electrocatalyst. The density functional theory results uncover that the FeCo0.68OOH-Pd0.026 optimizes the binding energies of ⁎O and ⁎OOH, and accelerates the OER kinetics. The rationally designed FeCo0.68OOH-Pd0.026 exhibits excellent OER activity and reliability, manifesting a Tafel slope of 37.5 mV dec-1, a low overpotential of 265.1 mV at 10 mA cm-2, which has the potential to realize the large-scale implementation of water splitting.