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

In this study, a novel SnS/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 SnS nanoplates. UV/Vis diffuse reflectance spectroscopy (DRS) indicated that SnS/BiOBr composites possessed stronger visible-light absorption. The as-fabricated SnS/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 SnS. The enhanced photocatalytic activity was attributed to the closely contacted interface between BiOBr and SnS, 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 (O) were the main active species in the photocatalytic oxidation process. The mechanism of the excellent photocatalytic activity of SnS/BiOBr heterojunction composite was also discussed.