Mesoporous TiO2@Ag3PO4 photocatalyst with high adsorbility and enhanced photocatalytic activity under visible light

Abstract Mesoporous TiO 2 with 20 nm particle size was attached onto the surface of Ag 3 PO 4 crystals (200 nm to 400 nm in diameter). The special mesoporous TiO 2 shell hindered Ag 3 PO 4 from being dissolved into the solution, which reduced the number of aqua-Ag ions generated from Ag 3 PO 4 crystal, thereby protecting Ag 3 PO 4 from photocorrosion without decreasing its visible-light absorption. TiO 2 @Ag 3 PO 4 catalyst had high visible-light photocatalytic activity because of the presence of narrow-band-gap Ag 3 PO 4 . Compared with pure Ag 3 PO 4, the adsorption capacity of TiO 2 @Ag 3 PO 4 toward rhodamine B (RhB) increased from 1.1% to 14.8% because of the mesoporous structure of TiO 2 . The composite TiO 2 @Ag 3 PO 4 catalyst with molar ratio 0.5:1 exhibited the highest degradation efficiency. About 100 mL of 10 mg/L RhB can be totally degraded within 12 min in presence of 0.05 g of catalyst.