Enhancing the hydrogen evolution reaction by non-precious transition metal (Non-metal) atom doping in defective MoSi2N4 monolayer

Abstract

Two-dimensional (2D) hydrogen evolution reaction (HER) electrocatalysts have attracted great attention due to their unique electronic properties and high activities. Recently, a new 2D monolayer material of MoSi2N4 has been successfully synthesized and its semiconducting property and excellent ambient stability have also been demonstrated (Science 2020, 369, 670). Here, a systematic screening of catalysts for HER among N- and Si-defective MoSi2N4-supported single non-precious transition metal (TM) and non-metal (NM) atom catalysts is performed by means of density functional theory (DFT) calculations. Interestingly, the single O/P/Fe/Nb atom doped N-(Si-) defective MoSi2N4 monolayer were found to possess excellent HER performance presenting a near-zero ΔGH, which is comparable to or even better than the state-of-the-art Pt-based materials. Moreover, the novel HER activities of some TM doped structures were explained by the “states filling” model. The energy level of the first available unoccupied states for accommodating hydrogen drops after the introduction of TM atom, which modulates the hydrogen binding strength. This work opens the door for the application of MoSi2N4 monolayer and other related 2D materials in the field of energy conversion.