Enhancement of the optical absorption of carbon group elements doped ZnS in the visible light range

Although the pristine ZnS can perform photocatalytic hydrogen production from water splitting, the reaction can not be driven by the visible light because of its wide energy band gap. Therefore, ZnS doped with carbon group elements (C, Si, Ge, Sn, Pb) has been investigated by using first-principles density functional theory calculations to understand the feasibility of the reaction driven by solar energy. All the geometrical structures are fully optimized. The electronic and optical properties of these structures have been calculated with the meta-GGA MBJ method and with projector augmented wave potential. The results show that all the doped structures have low formation energies, implying that the synthesis of the doped structures is not difficult in energy. Moreover, the absorptions of the doped structures in the visible light range are significantly enhanced, but their energy levels are still suitable for water splitting to generate hydrogen, which means that carbon group elements doped ZnS structures are promising candidate materials for water splitting driven by visible light. (C) 2017 Elsevier Ltd. All rights reserved.