Artificial modulated Lewis pairs for highly efficient alkaline hydrogen production

Nickel phosphides are competitive non-noble candidates for alkaline hydrogen evolution reaction (HER), however, their activities are insufficient due to the inert alkaline water dissociation, which hampers application in hydrogen production. Herein, we design a highly efficient electrocatalyst consisting of monocrystalline NiMoO4 nanorods modified by broccoli-like hierarchical Ni(PO3)(2)-Ni2P coupling with MoOx self-supported catalyst. As HER proceeds, catalytic performance gets better due to the dissolution of MoOx to further expose more nickel sites as Lewis base sites and in-situ formation of hydroxyl-ligands on the surface of loading nanoparticle as Lewis acid sites, which effectively integrate artificial frustrated Lewis pairs (FLPs) to respectively promote adsorption of H* and activation of H2O molecules. Moreover, the electron-transfer leads to the downshift of the D-band center of Ni, which helps optimizing desorption ability of H*. Therefore, such reconstructed catalyst exhibits extremely low overpotentials of 11 and 79 mV to afford 10 and 100 mA.cm(-2) in 1.0 M KOH with sustainable durability for over 110 h, outperforming most of reported advanced alkaline HER catalysts. Additionally, this catalyst used as cathode for overall alkaline water splitting at 10 and 100 mA.cm(-2) with only 1.48 and 1.57 V, showing its broad application prospect in practical large-scale hydrogen production.

Automated summary

In this study, a highly efficient electrocatalyst consisting of modified NiMoO4 nanorods and MoOx catalyst was designed. Integration of artificial frustrated Lewis pairs improved the catalytic efficiency of alkaline HER. The reconstructed catalyst exhibited low overpotentials and sustainable durability, showing great potential for large-scale hydrogen production.