Fabrication and Photocatalytic Activity of BiPO4@Ag3PO4 Core/Shell Heterojunction

BiPO4@Ag3PO4 core/shell heterojuction photocatalyst was synthesized through a facile hydrothermal process followed by the ion-exchange method. The morphology, crystallinity, composition, and photophysical properties of the catalyst were systematically investigated by scanning electron microscope(SEM), X-ray diffraction(XRD), energy dispersive X-ray analysis, UV-Vis diffuse reflectance spectrophotometer(DRS) and X-ray photoelectron spectroscopy(XPS). Meanwhile, Rhodamine B(RhB) was chosen as the target pollutant to evaluate the photocatalytic activity of BiPO4@Ag3PO4 photocatalyst under the visible light and simulated sunlight irradiation, respectively. The results show that RhB was almost totally degraded in 60 min under visible-light irradiation and in 40 min under sunlight irradiation, respectively. The BiPO4@Ag3PO4 core/shell heterojunction photocatalyst displayed enhanced photocatalytic activity against RhB, which is attributed to the effective charge separation by the core/shell heterojuction between the Ag3PO4 and BiPO4. Active species detection experiments proved that during the process of degradation of pollutants over the core/shell microrods, the main mechanism was the direct oxidation process by the photo-induced holes. Ag3PO4 shell can improve the absorption of the visible light effectively and also enhance the stability, dispersibility and photocatalytic activity of the photocatalyst. The BiPO4@Ag3PO4 photocatalysts show attractive potential applications in pollution control, water splitting and solar cell.