Atomically Interfacial Engineering on Molybdenum Nitride Quantum Dots Decorated N-doped Graphene for High-Rate and Stable Alkaline Hydrogen Production

The development of low-cost, high-efficiency, and stable electrocatalysts for hydrogen evolution reaction (HER) under alkaline conditions is a key challenge in water electrolysis. Here, an interfacial engineering strategy that is capable of simultaneously regulating nanoscale structure, electronic structure, and interfacial structure of Mo2N quantum dots decorated on conductive N-doped graphene via codoping single-atom Al and O (denoted as AlO@Mo2N-NrGO) is reported. The conversion of Anderson polyoxometalates anion cluster ([AlMo6O24H6](3-), denoted as AlMo6) to Mo2N quantum dots not only result in the generation of more exposed active sites but also in situ codoping atomically dispersed Al and O, that can fine-tune the electronic structure of Mo2N. It is also identified that the surface reconstruction of Al-OH hydrates in AlO@Mo2N quantum dots plays an essential role in enhancing hydrophilicity and lowering the energy barriers for water dissociation and hydrogen desorption, resulting in a remarkable alkaline HER performance, even better than the commercial 20% Pt/C. Moreover, the strong interfacial interaction (Mo-N bonds) between AlO@Mo2N and N-doped graphene can significantly improve electron transfer efficiency and interfacial stability. As a result, outstanding stability over 300 h at a current density higher than 100 mA cm(-2) is achieved, demonstrating great potential for the practical application of this catalyst.

Automated summary

A study reports an interfacial engineering strategy that regulates the nanostructure, electronic structure, and interfacial structure of Mo2N quantum dots on N-doped graphene via codoping with Al and O. This strategy enhances hydrophilicity, lowers energy barriers, and achieves remarkable alkaline hydrogen evolution reaction performance.