Ce-Doped FeNi-Layered Double Hydroxide Nanosheets Grown on an Open-Framework Nickel Phosphate Nanorod Array for Oxygen Evolution Reaction

The doping of foreign atoms into the electrocatalyst can effectively adjust the electronic structure and further improve the electrocatalytic activity. Here, we constructed a three-dimensional integrated electrode of Ce-doped FeNi LDH (LDH, layered double hydroxide) with an amorphous structure on a Ni foam-supported open-framework nickel phosphate nanorods array (donated as CFN@VSB-5/NF) via a hydrothermal-electrodeposition two-step process. The as-constructed CFN@VSB-5/NF electrocatalyst merely required an overpotential of 226 mV to generate a current density of 100 mA cm–2 with a Tafel slope of 43.1 mV dec–1, which was remarkably lower than FN@VSB-5/NF (η100 = 273 mV) without the addition of Ce. Also, the CFN@VSB-5/NF could continuously catalyze for 50 h at a current density of 500 mA cm–2 without obvious potential fluctuation, presenting appealing durability at a large current density. Further investigations revealed that the superior oxygen evolution reaction (OER) electrocatalytic performance should be attributed to the high intrinsic activity, optimal surface, and electronic structure of the as-constructed CFN@VSB-5/NF catalyst. Compared with the traditional FeNi-based catalysts, moreover, the present CFN@VSB-5/NF-integrated electrocatalyst also displayed stronger OER electrocatalytic activity and excellent stability at large current densities. Markedly, this work provides a path for constructing non-noble metal electrocatalysts with high OER activity.