Density functional theory study on electronic and photocatalytic properties of orthorhombic AgInS2

Band structures, density of states and photocatalytic properties of orthorhombic AgInS2 are calculated using density functional theory. The results show that orthorhombic AgInS2 has a direct band gap of about 2.09 eV, which is according to the experimental value. Calculated positions of the valence bands maximum and conduction bands minimum indicate that AgInS2 has strong redox ability to decompose organic pollutants and split water into hydrogen under visible light irradiation. Distortions in AgS4 and InS4 tetrahedra promote the separation of electron–hole pairs and the lighter effective mass of electrons facilitate the migration of electrons to the surface, resulting in improved photocatalytic performance.