Unraveling the Synergistic Effect of Tip‐enhanced Electric Field and Amorphization‐Derived Gradient Defect for Boosting Hydrogen Evolution

The surface amorphous design can provide more active sites due to their unusual atomic arrangements, adaptable electron configurations, and exceptional stability at heterointerface. Yet, the defects lattice arrangement in amorphous‐crystalline (A‐C) interfaces is still lacking of experimental observation and mechanistic explanations. Meanwhile, the transition from crystal to amorphous structure is difficult to control precisely and the excessive thickening of amorphous layers often lead to compromised electrochemical stability. Herein, the amorphous layer is controlled grafted at edges and tip of ZnCo 2 O 4 nanocones by in situ atomic layer phosphorization to construct A‐C interfaces. The resultant P‐ZnCo 2 O 4 exhibits a low hydrogen evolution reaction (HER) overpotential of 53 mV at 10 mA cm −2 , which is the best spinel‐based HER electrocatalysts. Advanced visual electron microscopy shows that a gradient defect layer with a thickness of 5–8 nm is created across A‐C transition area, and the internal arrangement exhibits a gradual change trend from point vacancy to 2D surface defects. Theoretical calculations reveal that high‐curvature tips and the gradient layer of defects can enhance the local electric field strength and for optimized the reaction energy barrier. This work emphasizes the effectiveness of uniform boundary effects and in situ formed active layers in enhancing electrochemical energy conversion.