Interfacial sp C–O–Mo Hybridization Originated High-Current Density Hydrogen Evolution

High-current density (≥1 A cm–2) is a critical factor for large-scale industrial application of water-splitting electrocatalysts, especially seawater-splitting. However, it still remains a great challenge to reach high-current density due to the lack of active and stable intrinsic catalytic active sites in catalysts. Herein, we report an original three-dimensional self-supporting graphdiyne/molybdenum oxide (GDY/MoO3) material for efficient hydrogen evolution reaction via a rational design of "sp C–O–Mo hybridization" on the interface. The "sp C–O–Mo hybridization" creates new intrinsic catalytic active sites (nonoxygen vacancy sites) and increases the amount of active sites (eight times higher than pure MoO3). The "sp C–O–Mo hybridization" facilitates charge transfer and boosts the dissociation process of H2O molecules, leading to outstanding HER activity with high-current density (>1.2 A cm–2) in alkaline electrolyte and a decent activity and stability in natural seawater. Our results show that high-current density electrocatalysts can be achieved by interfacial chemical bond engineering, three-dimensional structure design, and hydrophilicity optimization.