Construction of Mn0.3Cd0.7S/FeNi8-LDH S-scheme heterojunction for enhanced photocatalytic degradation of tetracycline under visible light

Abstract

The widespread application of antibiotics, such as tetracycline (TC), has led to severe environmental problems. Herein, the rod-like Mn0.3Cd0.7S (MCS) coupled with flower-like FeNi8-LDH self-assembled from nanosheets S-scheme heterojunction is successfully constructed by a simple physical ultrasonic-assisted combined with a grinding method. The optimized MCS/30FeNi8-LDH heterojunction exhibits excellent photocatalytic degradation of TC under visible light with a removal rate of 72.5% within 30min along with excellent cycling stability, which enhanced 14.5 and 1.68 times compared to those of pristine FeNi8-LDH and MCS. The correlation between S-scheme heterojunction and photocatalysis performance clarify the rapidly transfer pathway of photogenerated carriers between MCS and FeNi8-LDH. The trapping experiment confirms •O2- and h+ are the primary active species, with h+ playing a dominant role in the degradation process. The enhanced photocatalytic degradation performance can be attributed to the formation of S-scheme heterojunction with well-matched band alignment, which remains the powerful reduction capability of generated electrons of FeNi8-LDH and more robust oxidation capability of photogenerated holes of MCS. This work not only provides a potential solution for photocatalysis degrading TC, but also expands the S-scheme heterojunction construced strategy to the realm of energy storage and conversion.