First-principles investigations of electronic, optical, and photocatalytic properties of Au-adsorbed MoSi2N4 monolayer

The electronic, optical, and photocatalytic properties of Au-adsorbed MoSi 2 N 4 systems are predicted by first-principles calculations. Electronic structure analysis shows that the band gap is reduced from 1.89 eV (intrinsic MoSi 2 N 4 ) to 0 eV (MoSi 2 N 4 –9Au). Calculation results of density of states indicate that the valence band edge is mainly contributed by the Mo 4d state, whereas the conduction band edge is contributed by both the Mo 4d and Si 3p states. As the number of adsorbed Au atoms is increased, the absorption coefficient increases from 3.0 × 10 4 cm −1 to 5.6 × 10 4 cm −1 , meaning that more photons can be absorbed. Indeed, Au-adsorbed MoSi 2 N 4 monolayer shows greater potential for applications such as water splitting and CO 2 reduction based on redox potential analysis. The Au-adsorbed MoSi 2 N 4 structures can effectively change the properties of materials, offering great potential in different fields. ● The electronic, optical, and photocatalytic properties of Au-adsorbed MoSi 2 N 4 systems have been evaluated by first-principles calculations. ● The band gap is reduced from 1.89 eV (intrinsic MoSi 2 N 4 ) to 0 eV (MoSi 2 N 4 - n Au, n = 9). ● The Au adsorption process offers a simple means of adjusting the properties of MoSi 2 N 4 , which should lead to great potential in different fields. ● Based on redox potential and optical property analysis, MoSi 2 N 4 - n Au can be expected to show superior performance in applications such as water splitting and CO 2 reduction.