Regulating the active species of Ni(OH) using CeO: 3D CeO/Ni(OH)/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 vertically grown Ni(OH) nanosheets. As designed Ni(OH)/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 nanoparticles (NPs) of ∼3.3 nm in size are decorated on Ni(OH) nanosheets to design a highly efficient CeO/Ni(OH)/NOSCF electrocatalyst for the oxygen evolution reaction (OER). The CeO NP decorated Ni(OH)/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 and excellent stability under different overpotentials. The synergistic effect of producing more active species of Ni and accelerating the charge transfer for Ni(OH)/NOSCF by the introduction of CeO NPs is also investigated. These results demonstrate the possibility of designing energy efficient OER catalysts with the assistance of earth abundant CeO-based catalysts.