Controllable Fabrication of Regular Hexagon-Shaped SnS₂ Nanoplates and Their Enhanced Visible-Light-Driven H₂ Production Activity

SnS2 nanoplate-like products were fabricated via a facile hydrothermal process of a mixed solution containing SnCl4 and thiourea (SC(NH2)2) without organic capping agent, and their composition, crystallinity, and morphology can be adjusted by varying the SC(NH2)2/SnCl4 molar ratio. In particular, regular hexagon-shaped SnS2 nanoplates with an average size of ∼275 nm and thickness of ∼56 nm were attained when the SC(NH2)2/(SnCl4) molar ratio is 6:1. The obtained SnS2 nanoplates exhibit layered structures with exposed {001} facets and a single-crystalline feature, and its growth mechanism was proposed according to the hydrothermal time-dependent experimental results. The regular hexagon-shaped SnS2 nanoplates achieve high photocatalytic H2 production activity of 356 μmol h–1 under visible light (λ ≥ 420 nm) irradiation, much better than that of the irregular nanoplate-like products. The higher crystallinity and fewer defects of the regular hexagon-shaped SnS2 nanoplates compared to the irregular ones can more efficiently retard the photogenerated charge recombination, while the S atoms with higher density in the exposed {001} facets might be beneficial for the formation of H bonds with H2O molecules, which then cause good dispersity and photocatalytic activity for H2 production of the SnS2 nanoplates. These results demonstrate the potential application of SnS2 nanoplates in the photocatalytic H2 production field, and might provide guidance to the controllable syntheses of the family of MS2 photocatalysts with a highly efficient H2 production property.