Enhancement of the photocatalytic synchronous removal of Cr(vi) and RhB over RP-modified flower-like SnS2.

Abstract

Although photocatalysis is frequently employed to remove various pollutants in water, it still suffers from low efficiency due to the rapid recombination of photogenerated electrons and holes. In this study, a red phosphorus/tin disulfide (RP/SnS2) composite photocatalyst is fabricated by loading nano-sized RP on flower-like SnS2 films with a facile hydrothermal method. It is noteworthy that the 2D heterojunction formed between SnS2 and RP provided channels for the rapid transfer of photon-generated carriers and their effective separation. Furthermore, the separated electrons can react with absorbed O2 for the generation of superoxide radicals (˙O2−), thereby impacting the photocatalytic degradation oxidation reaction. The application of photocatalytic synchronous removal of Cr(vi) and RhB over RP/SnS2 was implemented first. Compared with pristine SnS2, the photocatalytic degradation activity of Cr(vi) and RhB over the RP/SnS2 composite was significantly enhanced and the kinetic rate constant reached 8.2, which is 10.8 times that of pristine SnS2. Moreover, the hybrid photocatalysts exhibited prominent reusability and stability. Therefore, a photocatalytic degradation mechanism and pathway of carriers are proposed in the study. Furthermore, it is considered that the present study is a promising method in the treatment of wastewater by photocatalysis.