Fe-based catalysts with the merits of the most abundant reserves in the crust, cheapest, and low toxicity, show significant superiorities to noble-metal catalysts for electrocatalytic water splitting. Fe₃O₄ as a member of Fe-based catalysts has been widely used for oxygen evolution reaction (OER). However, it is rarely applied for Hydrogen evolution reaction (HER) owing to the lack of inherent active sites for hydrogen absorption. Fe−N coordination bonds can act as active sites for electrocatalytic performance. Therefore, we reasonably designed and constructed Fe₃O₄/g-C₃N₄ heterojunction, where abundant Fe−N bonds acting as HER active sites were formed with the aid of rich Pyridine N of g-C₃N₄. Activity characterization result indicates the optimized 50%-Fe₃O₄/g-C₃N₄ heterojunction exhibits excellent HER performance with a low overpotential of 160 mV at 10 mA cm⁻², a low Tafel slope of 77.18 mV dec⁻¹, and outstanding cycle stability. Density functional theory (DFT) calculation demonstrates that the enhanced electrocatalytic performance stems from the Fe−N bonding interaction, which endows 50%-Fe₃O₄/g-C₃N₄ with lower water dissociation barrier and a moderate Gibbs free energy of hydrogen adsorption (ΔG_H*) in comparison with pristine Fe₃O₄ and g-C₃N₄.

铁基催化剂具有地壳储量最丰富、价格便宜、毒性低等优点，在电催化水分解方面表现出较贵金属催化剂显着的优越性。Fe ₃ O ₄作为铁基催化剂的一员已广泛应用于析氧反应(OER)。然而，由于缺乏固有的吸氢活性位点，它很少应用于析氢反应（HER）。Fe−N 配位键可以作为电催化性能的活性位点。因此，我们合理设计并构建了Fe ₃ O ₄ /gC ₃ N ₄异质结，借助gC ₃ N ₄丰富的吡啶N形成丰富的Fe−N键作为HER活性位点。活性表征结果表明，优化的50%-Fe ₃ O ₄ /gC ₃ N _{4异质结表现出优异的HER性能，在10 mA cm} ^-2下具有160 mV的低过电势，77.18 mV dec ^-1的低塔菲尔斜率，以及出色的HER性能。循环稳定性。密度泛函理论（DFT）计算表明，增强的电催化性能源于Fe−N键合相互作用，赋予50%-Fe ₃ O ₄ /gC ₃ N ₄较低的水解离势垒和适度的氢吸附吉布斯自由能(ΔG _{H* ) 与原始 Fe 3} O ₄和 gC ₃ N ₄相比。