Search

Rational modulation of surface reconstruction in the oxygen evolution reaction (OER) utilizing defect engineering to form efficient catalytic activity centers is a topical interest in the field of catalysis. The introduction of point defects has been demonstrated to be an effective strategy to regulate the electronic configuration of electrocatalysts, but the influence of more complex planar defects (e.g., twins and stacking faults), on their intrinsic activity is still not fully understood. This study harnesses ultrasonic cavitation for rapid and controlled introduction of different types of defects in the FeCoNi/FeAl2O4 hybrid coating, optimizing OER catalytic activity. Theoretical calculations and experiments demonstrate that the different defects optimize the coordination environment and facilitate the activation of surface reconstruction into true catalytic activity centers at lower potentials. Moreover, it demonstrates exceptional durability, maintaining stable oxygen production at a high current density of 300 mA cm−2 for over 120 hours. This work not only presents a novel pathway for designing advanced electrocatalysts but also deepens our understanding of defect‐engineered catalytic mechanisms, showcasing the potential for rapid and efficient enhancement of electrocatalytic performance. [ABSTRACT FROM AUTHOR]

Given that the oxygen evolution reaction (OER) faces challenges due to its sluggish kinetics, development of efficient and robust OER catalytic electrodes is critical for reducing the cost of hydrogen production through electrochemical water splitting. In this study, a biphasic CoNi/Zn(Fe,Al,Cr)2O4 coating, characterized by a densely organized stalagmite‐like microarray structure, is deposited on a commercial pure titanium plate, creating an exceptionally effective OER catalytic electrode. The formation of numerous metal/spinel oxide heterogeneous interfaces is demonstrated to enhance its electron transfer ability and conductivity. At high potentials, aluminum leaching and lattice oxygen consumption can facilitate deep surface reconstruction of highly active Fe‐doped CoNiOOH phase inducing electrochemical activation, further optimizing thermodynamic barrier of the fundamental reaction step. Ultimately, this electrode showcases exceptional OER catalytic performance (low overpotential of 248 and 335 mV to deliver the current density of 10 and 100 mA cm−2) compared to commercial IrO2 catalyst (overpotential of ≈310 mV at 10 mA cm−2). Moreover, it demonstrates high current stability sustaining a current density of 500 mA cm−2 for 100 h. This work deepens the comprehension of the surface reconstruction process in OER and, more broadly, introduces a new avenue for designing and enhancing the performance of catalytic materials. [ABSTRACT FROM AUTHOR]