Prussian-blue-analog derived hollow Co₃O₄/NiO decorated CeO₂ nanoparticles for boosting oxygen evolution reaction

Exploration of efficient, inexpensive, and stable electrocatalysts for oxygen evolution reaction (OER) is of great significance for energy conversion and storage. Currently, transition metal oxides (TMOs) show huge potential as electrode materials for OER due to their low-cost, rich redox chemistry and high chemical stability. In this work, we report a facile route for uniformly coating CeO₂ nanoparticles (NPs) on the surface of nickel cobalt Prussian blue analogue (NiCo-PBA) derived Co₃O₄/NiO hollow porous nanocubes (Co₃O₄/NiO HPN). The accurate control of CeO₂ content on the Co₃O₄/ NiO HPN (Co₃O₄/NiO@CeO₂ HPN) surface can effectively alter the surface electronic states, which tunes the ratio of Co²⁺/Co³⁺ and Ni²⁺/Ni³⁺ for creating abundant oxygen vacancies. The large surface area of hollow nanocubes derived from NiCo-PBA with porous structure offers more active sites, resulting in the great promotion of OER activity. The prepared Co₃O₄/NiO@CeO₂-2 HPN heterostructure exhibits remarkable OER performance with a low overpotential (290 mV at 10 mA·cm⁻²), small Tafel slope (66 mV dec⁻¹) and excellent durability. The present method opens a new avenue to the preparation of low-cost and efficient electrocatalysts in OER.