SnS2 Nanoplates with Specific Facets Exposed for Enhanced Visible-Light-Driven Photocatalysis

Graphical The sides face off : SnS 2 nanoplates dominated by {101} or {100} exposed facets are successfully prepared through a simple hydrothermal method and their facet-dependent band-energy diagrams are confirmed by combining spectroscopic analysis and theoretical calculations. Accordingly, SnS 2 nanoplates dominated by different exposed facets exhibit quite different photo-catalytic behaviours in target reactions. A facile hydrothermal strategy is developed for the synthesis of SnS 2 nanoplates with specific exposed facets. The crystallographic structure and the specific exposed facets of as-prepared SnS 2 are confirmed by X-ray diffraction, Raman spectroscopy and TEM analysis, and the surface electronic state and the chemical composition of samples are investigated by X-ray photoelectron spectroscopy (XPS). The band gaps of SnS 2 nanoplates are directly measured from UV/Vis absorption spectra, and their detailed band alignments are determined by Mott–Schottky plots and ultraviolet photoelectron spectroscopy (UPS) analysis, which are well supported by DFT calculations. Significant transient photocurrent responses under visible-light irradiation from photoelectrochemical analysis reveal that SnS 2 samples are active and stable visible-light-driven photocatalysts and that SnS 2 nanoplates dominated by {101} exposed facets should be better photocatalysts than those dominated by {100} exposed facets. The photocatalytic activities of SnS 2 nanoplates are examined in two typical reactions, that is, rhodamine B (RhB) degradation and hydrogen production from water splitting. As expected, SnS 2 nanoplates dominated by {101} exposed facets exhibit distinctly higher activity than those dominated by {100} exposed facets in the photocatalytic RhB degradation. For hydrogen production from water splitting, SnS 2 nanoplates dominated by {101} exposed facets exhibit significant photocatalytic activity resulting from their suitable band edges to realize the photocatalytic redox reaction, in great contrast to the inactive SnS 2 nanoplates dominated by {100} exposed facets.