Improved hydrogen evolution reaction performance of molybdenum boride via oxygen-functionalization: A first-principles study

Molybdenum-based materials (MoB and MoO₂) have been experimentally reported to exhibit outstanding electrocatalytic hydrogen evolution reaction (HER) activity. It is interesting to further explore the impact of introducing O atoms into MoB on its HER activity. Herein, the HER catalytic performances of the pristine MoB and O-doped MoB with different O concentrations in acidic and alkaline media were investigated by first-principles calculations. It was found that MoB–O_0.5, MoB–O_0.625 and MoB–O_0.75 show excellent HER activities, even surpassing the performance of Pt (111). Moreover, the introduction of one O atom into MoB surface (MoB–O_0.125) can facilitate H₂O dissociation by the formation of hydrogen bond and further improve the HER performance in alkaline medium. Our findings offer the new perspectives into the design of MoB-based efficient HER catalysts.