MoS2 quantum dots-bridged g-C3N4/AgI Z-scheme photocatalyst for efficient antibiotic degradation and bacteria inactivation under visible light

MoS 2 quantum dots decorated g-C 3 N 4 /AgI Z -scheme heterostructures were successfully prepared and applied in tetracycline hydrochloride (TCH) degradation and Escherichia coli ( E. coli ) disinfection upon visible light exposure. The ternary heterojunction achieved highly efficient photocatalytic abilities, which could eliminate 82.8 % of TCH in 50 min and absolutely kill E. coli in 40 min, superior to those of bare g-C 3 N 4 , AgI, g-C 3 N 4 /MoS 2 and g-C 3 N 4 /AgI binary composites. Benefiting from the Z -scheme heterostructure, the separation and migration efficiency of charge carriers in the g-C 3 N 4 /MoS 2 /AgI composite was greatly improved, which led to more effective production of predominant O 2 − and OH during the photocatalytic process. This work delivered an example of highly efficient composite photocatalyst and discussed the role of MoS 2 QDs as charge transfer mediator in Z -scheme photocatalytic system.