Topology-engineered metallic glass metamaterial-supported NiMo nanoglass catalysts for ultra-efficient water splitting.

Electrocatalytic water splitting represents a cornerstone for sustainable hydrogen production, yet its industrial implementation remains constrained by inherent trade-offs among activity, stability and mass transport efficiency. Achieving concurrent optimization of these properties in an integrated catalyst is challenging, as they are dictated by structures spanning multiple length scales. Here, we report a multiscale metamaterial catalyst design strategy that couples topology-engineered transport pathways with nanoglass heterointerface-regulated catalytic activity. Specifically, multiscale metamaterial catalysts (i.e. NiMo@Zr MMCs) are constructed by integrating micro-laser powder bed fusion-fabricated Zr-based metallic-glass triply periodic minimal surface scaffolds with pulsed-electrodeposition (PED)-derived NiMo nanoglass heterostructures. The Gyroid architecture provides enhanced permeability, efficient electrolyte/gas transport and mechanical robustness, while the abundant amorphous-amorphous interfaces within the NiMo nanoglass heterostructure optimize the local electronic environment and catalytic activity. Through the synergistic integration of topology engineering, metallic-glass scaffolds and nanoglass interface engineering, the resulting NiMo@G catalyst delivers record-low cell voltages for overall water splitting (1.438 V at 100 mA cm-2 in 1 M KOH) and outstanding long-term durability (>200 h). This work extends the concept of metamaterial catalysts from topology-controlled transport design to the coupling of transport and catalytic-interface engineering across multiple length scales, providing a generalizable framework for next-generation electrocatalysts.