Highly efficient visible light degradation of Rhodamine B by nanophasic Ag₃PO₄ dispersed on SBA-15

To improve the catalytic property and reduce the silver consumption, nanophase of silver phosphate was dispersed on the SBA-15 to form the Ag ₃PO₄-SBA-15 nanocomposites. Transmission electron microscopy revealed that crystals of Ag₃PO₄ of about 14 nm were well dispersed on the surfaces of the SBA-15. Although the surface area of Ag₃PO₄-SBA-15 decreased compared to the original SBA-15 because of blocked pores by Ag₃PO₄, there was sufficient adsorption of Rhodamine B leading to its efficient catalytic degradation in visible light. The silver content of the nanocomposite was only 1.69 wt% compared to the 77.3% for pure Ag₃PO₄ but their catalytic performance was about the same because of well-dispersed nanophase of Ag ₃PO₄ in the former. Under the visible illumination for 70 min, the Rhodamine B concentration decreased to about 10% in both cases suggesting that the new nanocomposite is a highly efficient and cost-effective photocatalyst.