Interfacial Chemical Bond Modulation of Co 3 (PO 4 ) 2 -MoO 3- x Heterostructures for Alkaline Water/Seawater Splitting.

The development of a high current density with high energy conversion efficiency electrocatalyst is vital for large-scale industrial application of alkaline water splitting, particularly seawater splitting. Herein, we design a self-supporting Co(PO)-MoO/CoMoO/NF superaerophobic electrode with a three-dimensional structure for high-performance hydrogen evolution reaction (HER) by a reasonable devise of possible "Co-O-Mo hybridization" on the interface. The "Co-O-Mo hybridization" interfaces induce charge transfer and generation of fresh oxygen vacancy active sites. Consequently, the unique heterostructures greatly facilitate the dissociation process of HO molecules and enable efficient hydrogen spillover, leading to excellent HER performance with ultralow overpotentials (76 and 130 mV at 100 and 500 mA cm) and long-term durability of 100 h in an alkaline electrolyte. Theoretical calculations reveal that the Co(PO)-MoO/CoMoO/NF promotes the adsorption/dissociation process of HO molecules to play a crucial role in improving the stability and activity of HER. Our results exhibit that the HER activity of non-noble metal electrocatalysts can be greatly enhanced by rational interfacial chemical bonding to modulate the heterostructures.