Regulating the active species of Ni(OH)(2) using CeO(2): 3D CeO(2)/Ni(OH)(2)/carbon foam as an efficient electrode for the oxygen evolution reaction

Three dimensional (3D) N, O and S doped carbon foam (NOSCF) is prepared as a substrate for in situ vertically grown Ni(OH)(2) nanosheets. As designed Ni(OH)(2)/NOSCF possesses strong electrostatic interactions with OH(–) ions due to many C[double bond, length as m-dash]O groups existing in NOSCF, which can facilitate the formation of crucial NiOOH intermediates during the OER process. CeO(2) nanoparticles (NPs) of ∼3.3 nm in size are decorated on Ni(OH)(2) nanosheets to design a highly efficient CeO(2)/Ni(OH)(2)/NOSCF electrocatalyst for the oxygen evolution reaction (OER). The CeO(2) NP decorated Ni(OH)(2)/NOSCF not only exhibits a remarkably improved OER performance with an onset potential of 240 mV, outperforming most reported non-noble metal based OER electrocatalysts, but also possesses a small Tafel slope of 57 mV dec(–1) and excellent stability under different overpotentials. The synergistic effect of producing more active species of Ni(III/IV) and accelerating the charge transfer for Ni(OH)(2)/NOSCF by the introduction of CeO(2) NPs is also investigated. These results demonstrate the possibility of designing energy efficient OER catalysts with the assistance of earth abundant CeO(2)-based catalysts.