Effect of ethylene glycol on the growth of hexagonal SnS2 nanoplates and their optical properties

Hexagonal SnS2 particles were synthesized via a solvothermal method using a mixture of ethylene glycol (EG) and distilled water as solvent. Hexagonal SnS2 nanoplates of more regular morphology were obtained when the volumetric ratio of EG to distilled water (EG:H2O) decreased from 4:1 to 1:4. The effect of EG on the growth of hexagonal SnS2 nanoplates was investigated and a growth restraint mechanism in [0 0 1] was proposed. A large band gap of 3.52 eV of the hexagonal SnS2 nanoplates may facilitate electron injection from photo-excited dye molecules in dye-sensitized solar cells (DSSCs). A photoluminescence (PL) peak at 761 nm under excitation at 507 nm was also observed in the hexagonal SnS2 nanoplates. The 761 nm emission, which is within the absorption band of the Ru-based dye, is expected to make sufficient utilization of solar energy in DSSCs.

► A mixture of EG and distilled water as solvent.
► SnS2 nanoplates of improved morphology form with decreased volumetric ratio EG:H2O.
► Growth restraint mechanism of hexagonal SnS2 nanoplates in [0 0 1].
► Hexagonal SnS2 nanoplates with a large band gap of 3.52 eV.