In Situ Growth of Hollow Trimetallic Nanocubes on Nickel Foam for the Electrocatalytic Oxygen Evolution Reaction

Abstract Nanomaterials derived from Prussian blue (PB) and its analogues (PBAs) possess uniform active centers and large surface areas, which can be applied in the field of electrocatalysis. In this study, nickel‐iron‐cobalt trimetallic PBAs, that is, NiFeCo(4 : 1)PBA nanocubes, were grown in situ on nickel foam (NF), which was subsequently calcined in air to obtain a composite electrode, NiO/FeO X /Co 3 O 4 @NF, with a loose porous hollow nanocube morphology. This structure remarkably enlarged the contact area between the electrolyte and the catalyst. In addition, a synergistic effect among these metallic oxides expedited oxygen evolution reaction (OER) kinetics. The Tafel slope (71.25 mV dec −1 ) toward OER of the constructed electrode is fairly small, much lower than that of our prepared bimetallic oxides@NF electrodes. The enduring stability is more than 22 h. This work indicates that, through morphology and composition control, the electrocatalytic performance of the designed electrode can be effectively improved.