Constructing a novel S-scheme Ag/MIL-68(In)-NH2/Bi4O7 plasmonic heterojunction with boosted visible light catalytic activity

Environmental pollution caused by the overusage and uncontrolled discharge of antibiotics such as amoxicillin will endanger public health and ecosystems. Herein, a novel Ag/MIL-68(In)-NH2/Bi4O7 plasmonic heterojunction has been successfully prepared through a two-step route followed by photoreduction for environmentally friendly photocatalytic amoxicillin degradation. Ag/MIL-68(In)-NH2/Bi4O7 displayed the most efficient photocatalytic performance, which was 3.7 and 3.2 times that of Bi4O7 and MIL-68(In)-NH2, respectively. The superior photocatalytic activity was directly linked to its large surface area and localized surface plasmon resonance (LSPR) effect, which provides more active sites and effectively promotes visible light absorption. Moreover, the degradation path of amoxicillin was explored in detail by combining Gaussian software calculation with liquid chromatography-mass spectrometry (LC-MS) analysis. Finally, a series of characterizations and simulations were carried out to demonstrate the S-scheme photocatalytic mechanism.