Photocatalytic Performance of Hierarchical TiO2/Ag3PO4 Composite Under Visible-light Illumination

Urchin-like TiO2 nanomaterial with hierarchical structure (PTHSs) was prepared, then Ag3PO4 nanomaterial with visible-light response was deposited on the hierarchical TiO2 by simple deposition precipitation method, thus a series of PTHSs/Ag3PO4 composites with efficient visible-light photodatalytic performance and stability was synthesized. The photocatalytic performance of the PTHSs/Ag3PO4 composites for degrading Rhodamine B (RhB) was analyzed. The results show that the photocatalytic performance of PTHSs/Ag3PO4 composite is significantly superior to that of pure Ag3PO4 and that of TiO2(P25)/Ag3PO4 composite. The composite with a PTHSs/Ag3PO4 molar ratio of 1 : 1 showed the best photocatalytic performance and it could decolorize the RhB completely in 6 min under visible light illumination. This is because that the urchin-like TiO2 nanomaterial can provide more load sites than TiO2 nanoparticle for loading Ag3PO4. And the hierarchical TiO2 can also improve the contact between the surfaces of TiO2 and Ag3PO4 so that the separated efficiency of photo-generated electrons-holes by Ag3PO4 is improved. Meanwhile during the photodegradation process, a little Ag+ on the surface of Ag3PO4 are gradually reduced to Ag-0, by the plasma resonace effect of which, the absorption and conversion capability of the composite for photon are enhanced and the photocatalytic performance of the composite material for degrading dyes is further enhanced.