Enhancing the d/p-Band Center Proximity with Amorphous-Crystalline Interface Coupling for Boosted pH-Robust Water Electrolysis

Rationalizing non-precious pH-robust electrocatalysts is a crucial priority and required for multi-scenario hydrogen production customization. Herein, an amorphous–crystalline CoBO_x/NiSe heterostructure is theoretically profiled and constructed for efficient and pH-robust water electrolysis. The crystalline lattice confinement induces a Co-Co bond shortening and a B-site delocalization on amorphous CoBO_x, resulting in a decreased d-p band center difference (Δε_d-p) toward the balanced intermediates adsorption/desorption. Accordingly, the CoBO_x/NiSe heterostructure exhibits efficient and robust hydrogen/oxygen evolution reaction (HER/OER) catalytic activity in different electrolytes. Of particular note, it achieves ultralow overpotentials in both the beyond-Pt HER (14.5 mV) and OER (229.1 mV) at 10 mA cm⁻² under an alkaline electrolyte, and reaches an industrial-level OER current density of 2 A cm⁻². Water electrolysis is stably delivered with a low η₁₀ voltage of 1.48 V. The incorporation of such d-p orbitals at the amorphous–crystalline interface puts forward new opportunities in rationally designing advanced non-precious electrocatalysts for water electrolysis.