Synthesis and photoelectric properties of visible sensitive SnS2-linked graphene composites

SnS2-linked graphene (SnS2-rGO) was synthesized from graphene and SnCl2 under mild reducing conditions. X-ray diffraction and transmission electron microscopy of the SnS2-rGO samples confirmed the presence of SnS2 nanoplates that were highly dispersed and well linked onto the thin layered graphene. The SnS2-rGO was introduced as a working electrode into dye-sensitized solar cells (DSSCs) because of its good transparency and electric conductivity. The SnS2-rGO was mixed with p-25 TiO2 powders to make an anode electrode of DSSCs. The graphene and SnS2 exhibited a synergistic effect. Compared to p-25 TiO2-double layered DSSC, the SnS2-rGO-TiO2(upper)/TiO2(bottom) double layered anode film enhanced the energy conversion efficiency considerably; the efficiency for the 1.0 wt.% SnS2-rGO-TiO2(top)/TiO2 (bottom)-DSSC was approximately 5.47%. A potential energy model for electron transfer among TiO2, SnS2-rGO-TiO2, and dye was suggested on the basis of ultraviolet visible spectroscopy and cyclic voltammetry which showed a good relationship with the photovoltaic efficiency. (C) 2014 Elsevier B.V. All rights reserved.