Prediction of quaternary SnGeS2As4 monolayer as a promising photocatalyst in water splitting: A DFT study

Abstract The SnGeS 2 As 4 monolayer was studied by first-principles calculations to estimate its potential for used as photocatalyst in water splitting process. The stability of this structure is confirmed based on the analysis of its phonon dispersion and AIDM simulation. The electronic features including density of state (DOS), band structure, and Bader charge were calculated. These data show the role of each constitute element in the formation of covalent π− and σ−bonds, which play important role in stabilizing the buckled honeycomb structure. Besides, the DOS and band structure also provide information regarding to the high light absorption rate α(ω) of 10 5 –10 5 cm −1 . The positions of valence band maximum (VBM) and conduction band minimum (CBM) are suitable for generation of hydrogen and oxygen gases. The SnGeS 2 As 4 monolayer also has optimal work function 5.16 eV for water splitting process and a rather high solar-to-hydrogen efficiency η STH = 13.11%. It is worth to note that SnGeS 2 As 4 monolayers with strains ranging from −2% to 6% are still capable to trigger redox reactions in the water splitting process. Moreover, the tensile trains slightly increase the light absorption rates. Such characteristics not only make SnGeS 2 As 4 monolayer a suitable photocatalyst for water splitting but also ensure its performance in wider range of applications