Two-dimensional AlBiX3(X = S, Se, Te) monolayers for photocatalytic water splitting hydrogen evolution reaction under the irradiation of solar light

Abstract

The feasibility and solar-to-hydrogen efficiency (ηSTH) for the two-dimensional AlBiS3, AlBiSe3, and AlBiTe3 monolayers with the solar light photocatalytic hydrogen evolution reaction (HER) are explored by using the first-principles calculations. The geometrical structures of these monolayers are designed and fully relaxed. The stabilities of the obtained configurations have been validated by phonon dispersion and ab initio molecular dynamics simulations; at the same time, the HER feasibility is examined with the bandgap, band edges, the density of states, effect of strain engineering, mobility, and optical absorption. The results show that the AlBiS3, AlBiSe3, and AlBiTe3 monolayers possess indirect bandgaps of 2.44/3.20, 1.87/2.41, and 0.97/1.35 eV by HSE06/GW, respectively. The apparent difference between the electron and hole mobilities is identified, and obvious absorption within the range of the visible and UV lights implies the newfound monolayers can well absorb the solar light. Notably, the band edges of the AlBiS3 and AlBiSe3 monolayers could match HER conditions, and the moderate Gibbs free energy changes are suitable for HER, which means the AlBiS3 and AlBiSe3 monolayers could achieve HER, but the AlBiTe3 one could not. In addition, themaximum ηSTH can reach the theoretical limit of 17.51%, implying the monolayer can efficiently drive HER with solar light. Therefore, the AlBiS3 and AlBiSe3 monolayers are promising materials for solar light photocatalytic HER.