Ag2O nanoparticles decorated TiO2 nanofibers as a p-n heterojunction for enhanced photocatalytic decomposition of RhB under visible light irradiation

TiO2 nanofibers were successfully prepared by electrospinning method using tetrabutyl titanate, glacial acetic acid, PVP and methanol as the precursors. Ag2O/TiO2 composite nanofibers were then prepared by decorating the surface of TiO2 nanofibers with Ag2O nanoparticles (NPs) through a wet-chemical precipitation reaction under a certain amount of AgNO3 and NaOH. The photocatalytic properties of the as-prepared samples were tested by photocatalytic decomposition of RhB aqueous solution under visible light irradiation. Comparing with bare TiO2 nanofibers and pure Ag2O, the Ag2O/TiO2 composite with optimal mass ratio of Ag2O to TiO2 (40 wt %) exhibited the highest photocatalytic activity in decomposition of RhB. The enhanced photocatalytic activity of the composite was attributed to the fast separation of the photo-generated electron-hole pairs in the Ag2O/TiO2 interface in which a p-n heterojunction is formed and the high visible light absorption efficiency of Ag2O/TiO2 nanofibers.