Surface modification of electrocatalysts is a convenient strategy for addressing the drawbacks arising from the sluggish kinetics of the oxygen evolution reaction (OER). However, the preparation of electrocatalysts usually involves complex procedures, rendering investigation of the catalytic mechanism difficult. In this study, S-modified FeOOH electrocatalysts were prepared via a facile hydrothermal method at 120 °C. The electrocatalyst exhibited an outstanding OER performance with an overpotential of 254 mV at 50 mA·cm⁻². Morphological, structural, and electrochemical characterizations revealed that Fe ion is the most important active center. The effect of S on the catalytic process was investigated based on the steric hindrance for OH* adsorption, changes in ΔG of the rate-determining step, and coordination mode of the active species. This is the first report on the formation of an (Fe-S)-O* bond that plays a key role in enhancing the electrochemical performance.

电催化剂的表面改性是解决因放氧反应（OER）动力学缓慢而产生的缺点的便捷策略。然而，电催化剂的制备通常涉及复杂的程序，使得难以研究催化机理。在这项研究中，S改性的FeOOH电催化剂通过简便的水热法在120°C下制备。该电催化剂具有出色的OER性能，在50 mA·cm ^-2时的过电势为254 mV。形态，结构和电化学特征表明，Fe离子是最重要的活性中心。基于OH *吸附的空间位阻，速率决定步骤ΔG的变化以及活性物质的配位模式，研究了S对催化过程的影响。这是关于（Fe-S）-O *键形成的首次报道，该键在增强电化学性能中起关键作用。