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

Abstract

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.