Hierarchical Cu2ZnSnS4 microsphere as sonocatalyst for the degradation of Rhodamine B and reduction of Cr(VI)

We report the experimental realization of using copper zinc tin sulfide (Cu 2 ZnSnS 4 ) material for sonocatalytic application for the first time. Hierarchical Cu 2 ZnSnS 4 microspheres were synthesized via a facile one-pot hydrothermal method and characterized systematically. Aggregated Cu 2 ZnSnS 4 nanosheets with an average thickness of ~ 20 nm formed a highly open hierarchical structure. The hierarchical Cu 2 ZnSnS 4 microspheres displayed remarkable sonocatalytic activity both in Rhodamine B degradation and in Cr(VI) reduction. The detailed sonocatalytic experiments revealed that Rhodamine B dye degraded up to 96.4% in 14 min and Cr(VI) reduced up to 98.7% in 10 min and both Rhodamine B degradation and Cr(VI) reduction followed pseudo-first-order kinetics. The reusability tests confirmed that the hierarchical CZTS microspheres have proper stability after 4 consecutive cycles. Moreover, the effects of initial dye concentration, various scavengers, and oxidants on the sonocatalytic RhB degradation process have also been investigated. Furthermore, the plausible mechanism of the sonocatalytic degradation in the presence of hierarchical CZTS microspheres was proposed.