Interfacial Mo–O–W Bonds Improve the Photodegradation Performance of a Bi₂MoO₆/WO₃ Z-Scheme Heterojunction

Interface engineering has been proven to be a promising strategy for regulating carrier transport. Herein, an interfacial Mo-O-W bond was constructed between Bi₂MoO₆ nanospheres and WO₃ quantum dots. It served as a fast transfer channel for interfacial photogenerated carriers, resulting in the formation of a direct Z-scheme heterojunction. The Z-scheme heterojunction not only maximized the redox ability but also exhibited enhanced separation and transfer efficiency of photogenerated carriers. Thereby, it exhibited excellent degradation activity and reusability for different simulated pollutants (levofloxacin, rhodamine B, and methylene blue) under LED irradiation, and its photocatalytic rate is approximately doubled. Unexpectedly, a considerable amount of H₂O₂ was formed via a direct one-step two-electron oxygen reduction reaction process, which played a significant role in the photodegradation process, even surpassing the role of electrons/holes as active species. Furthermore, the photodegradation pathway of levofloxacin by the Z-scheme heterojunction was analyzed. This study could provide insights into establishing an interfacial chemical bond, modulating charge transfer, and the photodegradation mechanism.