Newfound 2D In2S3 allotropy monolayers for efficient photocatalytic overall water splitting to produce hydrogen

Abstract

Allotropy structures may induce different electronic and optical properties, which implies that one can acquire novel performance by screening its allotropy structures. Here, we demonstrate that two In2S3 allotropy monolayers with excellent photocatalytic performance for water splitting to produce hydrogen are screened from 1038 In2S3 allotropy monolayers. The phonon dispersions are calculated for 39 allotropes with the lowest formation energies, which confirms that 16 allotropes have dynamic stability, including the only one reported in the literature. The results of overpotentials of band edges demonstrate that 8 allotropes match the potential requirements of overall water splitting. The thermodynamic stability of these allotropes is further confirmed for the obtained allotropes. Then, two allotropes with maximum solar-to-hydrogen efficiency of 17.78% and 29.32% are screened. The Gibbs free energy with the solvent effect indicates that one allotrope can proceed photocatalytic hydrogen/oxygen evolution reactions spontaneously. Therefore, the newfound In2S3 allotropy monolayers have potential applications in photocatalytic overall water splitting for hydrogen generation.