II/Z-type Bi2MoO6/Ag2O/Bi2O3 Heterojunction for Photocatalytic Degradation of Tetracycline under Visible Light Irradiation

Construction of heterojunction can effectively suppress the swift recombination of photogenerated electrons and holes in photocatalyst. In this study, a II/Z-type Bi2MoO6/Ag2O/Bi2O3 heterojunction photocatalyst was synthesized using a solvothermal method combined with calcination. Various techniques were ultilized to examine the composition, morphology and photoelectrochemical properties of the as-prepared materials. The findings revealed that the optimal composition of the composite material was 25%ABOBM (with a mass ratio of Ag2O/Bi2O3 and Bi2MoO6 of 1 : 4). Under visible light irradiation, the degradation efficiency of tetracycline (TC) by 25%ABOBM reached 85.6%, which was significantly higher than that of Ag2O/Bi2O3 and Bi2MoO6, and maintained its good stability after three cycles of experiments. The enhanced photocatalytic performance of 25%ABOBM is attributed to the formation of heterojunctions and the unique morphologies among Ag2O, Bi2O3 and Bi2MoO6. Both h(+) and center dot O-2(-) are significant contributors, while center dot OH and O-1(2) have secondary roles in the degradation process of TC, as indicated by free radical capture experiment and electron paramagnetic resonance spectroscopy (EPR). Furthermore, the related photocatalytic mechanisms were explored, and the potential degradation pathways of TC were analyzed using liquid chromatography-mass spectrometry (LC-MS). This study offers a novel approach to the preparation of photocatalysts with dual heterojunctions and demonstrates their application in the degrading organic pollutants.