Harnessing Effective Electric Field Amplification and Intermetallic Hybridization via Nanoelectrode Superlattices to...

Electrocatalytic hydrogen evolution reaction (HER) offers a sustainable pathway for green hydrogen production, addressing growing energy demands while reducing fossil fuel dependence. However, existing electrocatalysts face challenges, including low current densities, excessive Pt reliance, and inefficient charge transfer. Here, ampere-level HER catalysis is achieved by introducing 2D nanoelectrode superlattices that boost electrocatalytic efficiency through two key concepts: i) Electric field amplification, where Ag nanoparticles serve as nanoelectrodes and their interparticle interactions within the superlattice are leveraged to concentrate local electric fields for facilitating charge accumulation and transfer. ii) Intermetallic Pt-Ag hybridization, which modulates electronic structure and electron distribution to enhance intrinsic catalytic activity. Notably, Ag hexagonal@Pt achieves the highest performance, delivering -15.88 A cm^-2 at -0.9 V vs RHE with 98% Faradaic efficiency and outperforming Ag standing@Pt and Ag disorganized@Pt by up to 8 fold. Moreover, it surpasses Pt/C by ≈934 fold and exhibits ≈4 fold reduction in overpotential at high current densities of ≥500 mA cm^-2 compared to other emerging electrocatalysts. Mechanistic studies reveal that optimizing spatial nanoelectrode arrangement is crucial for enhancing HER activity through synergistic electric field concentration and intermetallic hybridization. This work offers critical insights into advancing electrocatalysis for green hydrogen production and broader energy, chemical, and environmental applications.