Prediction of a Beryllium Phosphide Iodide Monolayer as a Photocatalyst for Water Splitting by Density Functional Theory

In this paper, a 2D monolayer compound of beryllium phosphide iodide, namely Be 2 PI monolayer, was systematically designed. Our design was conducted by computational simulation on the basis of density functional theory. The stability of the proposed structure was confirmed by cohesive energy evaluation and phonon dispersion mode analysis. We further investigated its promising electrical properties and applications. Based on our simulation, 2D Be 2 PI monolayer is a stable indirect semiconductor exhibiting a moderate bandgap of 2.41 eV, as obtained from Heyd–Scuseria–Ernzerhof (HSE06) theory. We also compared the positions of the band edge of the predicted monolayer with the redox potentials of water and found that it is a suitable material for use as a photocatalyst in water splitting. The calculated interesting properties for the designed 2D Be 2 PI monolayer suggest that this material can be employed in many practical usages, especially for use in pure hydrogen production. Graphical Abstract