Ag 2 S quantum dots based on flower-like SnS 2 as matrix and enhanced photocatalytic degradation

Abstract

Ag 2 S quantum dots were dispersed on the surface of SnS 2 nanoflowers forming a heterojunction via in-situ ion exchange to improve photocatalytic degradation of RhB. All samples exhibit the hexagonal wurtzite structure. The size of Ag 2 S@SnS 2 composites are ~ 1.5 μm flower-like with good crystallinity. Meanwhile, the Eg of 3% Ag 2 S@SnS 2 is close to that of pure SnS 2 . Consequently, the 3% Ag 2 S@SnS 2 composite displays the excellent photocatalytic performance under simulated sunlight irradiation with good cycling stability, compared to the pure SnS 2 and other composites. Due to the blue and yellow luminescence quenching, the photogenerated electrons and holes is effectively separated in the 3% Ag 2 S@SnS 2 sample. Especially, the hydroxyl radicals and photogenerated holes are main active species.