Two-dimensional MgAl2S4 as potential photocatalyst for water splitting and strategies to boost its performance

Exploring novel 2D water-splitting photocatalysts and finding strategies to boost their efficiency are important tasks in nowadays energy industry. Here, employing first-principle calculations, we predicted a novel 2D material, MgAl2S4 monolayer, and studied its potential applications in photocatalytic water splitting. 2D MgAl2S4 is noble-metal-free and possesses great thermal and dynamical stability. The cleavage energy is around 16 meV/>= 2 which is even lower than graphene, indicating the high feasibility for experimental fabrications. The band edge positions and the optical absorption spectra indicate the pristine MgAl2S4 monolayer can work as a photocatalyst upon ultraviolet irradiation. Its high electron mobility around 745 cm(2)v(-1)s(-1) and high conduction band minimum (CBM) position suggest a strong reduction ability. Furthermore, the oxidation ability and light absorbance can be significantly enhanced by a small tensile strain. The complementary marriage of MgAl2S4 and SnSe2 monolayers can form a direct z-scheme heterostructure, which can fully utilize the photocatalytic potential of both components.

Automated summary

Novel 2D material, MgAl2S4 monolayer, shows great potential as a photocatalyst for water splitting, as predicted by first-principle calculations. The material exhibits high thermal and dynamical stability, and can be experimentally fabricated with low cleavage energy. By applying tensile strain, its oxidation ability and light absorbance can be significantly enhanced. Additionally, combining MgAl2S4 with SnSe2 monolayer forms a more efficient direct heterostructure for photocatalysis.