In situ fabrication of Ag3PO4/TiO2 nanotube heterojunctions with enhanced visible-light photocatalytic activity

Abstract

Ag₃PO₄/TiO₂ nanotube (TNT) heterojunctions were fabricated via a facile in situ growth method. Hemispherical Ag₃PO₄ nanocrystals were uniformly grown on the TNT surface, and their size was confined to 5–10 nm. A joint area was distinctly observed between the Ag₃PO₄ nanocrystals and TNT, indicating the formation of a Ag₃PO₄/TNT heterojunction. Compared with pure Ag₃PO₄, the Ag₃PO₄/TNT heterojunction possesses more active sites, less bulk defects, more efficient electron–hole separation, as well as better dye adsorption properties, and thus exhibits a significantly elevated photocatalytic activity for Rhodamine B (RhB) degradation. The study of the reactive species demonstrates that the photocatalytic degradation of RhB over the Ag₃PO₄/TNT heterojunction is primarily driven by both photogenerated h⁺ and ˙OH radicals. This easily-fabricated Ag₃PO₄/TNT heterojunction with promising photocatalytic activity may find potential applications in energy and environmental related areas.