Enhanced visible-light photocatalytic degradation by Mn3O4/CeO2 heterojunction: a Z-scheme system photocatalyst

A Z-scheme system Mn3O4/CeO2 heterojunction was fabricated via a simple one-step hydrothermal method and further applied for photocatalytic Rhodamine B (RhB) degradation. In this work, the Mn3O4 nanoparticle was uniformly deposited on CeO2 nanorod surface, which formed a typical heterojunction. The presence of Mn3O4 in the Mn3O4/CeO2 heterojunction was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). X-ray photoelectron spectroscopy (XPS) verified that Mn was in the form of Mn3+ and Mn2+ in Mn3O4 nanoparticle. Noticeably, the Mn3O4/CeO2 heterojunction exhibited excellent photocatalytic activity for RhB degradation. The drastically enhanced photocatalytic performance could be attributed to improved light harvesting, efficient separation of the photo-generated electron-hole pairs and stronger electronic conductivity. Moreover, the photocatalytic mechanism was also explored on the Mn3O4/CeO2 heterojunction. This novel Mn3O4/CeO2 heterojunction was proved to have great potential for the degradation of organic contaminants in water.