Enhancement of urea oxidation reaction in alkaline condition via heterointerface engineering

Water electrolysis involving low energy barrier anodic urea oxidation reaction (UOR) is a promising way for hydrogen production. In this study, we present a superior heterostructured UOR electrocatalyst of (NiFeCo)S_x/FeOOH/NiFeCo(OH)_x supported on conductive Ni foam prepared using a simple, ultrafast, energy-saving single-step corrosion engineering method. Leveraging the high conductivity of the (NiFeCo)S_x, plentiful Fe³⁺ in the amorphous FeOOH, high catalytic activity of the NiFeCo(OH)_x, and abundant heterointerfaces, the resulting (NiFeCo)S_x/FeOOH/NiFeCo(OH)_x electrode exhibits remarkable electrocatalytic performance toward UOR under alkaline condition. The electrocatalyst shows an ultra-low potential of 1.36 V at 100 mA cm⁻², a small Tafel slope of 24.8 mV dec^–1, and excellent stability. Density functional theory calculation shows that the multiple heterointerfaces provide synergistic effect of shifting the d-band center to optimize the intermediate chemisorption energy, thus boosting the catalytic kinetics for catalyzing UOR.