In the present work, a series of Ag2S@Ag2SO4/CSN heterostructures were synthesized by the in situ fabrication of Ag2S/
Ag2SO4 on the chitosan matrix in a straightforward method. The structure, morphology, and properties of the prepared heterojunctions were analyzed by different characterization methods. The photocatalytic performance of the synthesized Ag2S@
Ag2SO4/CSN heterostructures was considered by rhodamine B (RhB) dye photodegradation. The best results were obtained
when the reaction was conducted by Ag2S@Ag2SO4/0.1CSN with enhanced photoactivity under sunlight irradiation (99.9%
degradation efficiency). In addition to the excellent photocatalytic activity, excellent recyclability and photostability under
Vis and sunlight irradiation were observed in the subsequent experiment, resulting from enhanced absorption of light and
decreased recombination of photogenerated electron–hole pairs in the photocatalysis process. Furthermore, the mechanism
of photocatalyst reactions is described in detail by density functional theory (B3LYP/ LANL2DZ). The bandgaps of Ag2S
and Ag2SO4 were calculated 2.47 and 1.37 eV, respectively