In-situ synthesis of novel Z-scheme SnS(2)/BiOBr photocatalysts with superior photocatalytic efficiency under visible light.

In this study, a novel SnS2/BiOBr heterojunction photocatalyst was synthesized via a facile in-situ growth strategy. The heterojunction interface was formed by loading BiOBr nanosheets on the surface of ultrathin hexagonal SnS2 nanoplates. UV/Vis diffuse reflectance spectroscopy (DRS) indicated that SnS2/BiOBr composites possessed stronger visible-light absorption. The as-fabricated SnS2/BiOBr heterojunction nanoplates exhibited considerable improvement in terms of photocatalytic activity for the degradation of rhodamine B (RhB) under visible light irradiation as compared with BiOBr and SnS2. The enhanced photocatalytic activity was attributed to the closely contacted interface between BiOBr and SnS2, thereby resulting in faster transfer of the photoinduced electron-hole pairs through their interface, as shown by the results of photoluminescence spectroscopy (PL) and photocurrent measurements. Radical trapping experiments demonstrated that holes (h+) and superoxide anion radicals (O2-) were the main active species in the photocatalytic oxidation process. The mechanism of the excellent photocatalytic activity of SnS2/BiOBr heterojunction composite was also discussed.