Microwave- and Formaldehyde-Assisted Synthesis of Ag-Ag3PO4 with Enhanced Photocatalytic Activity for the Degradation of Rhodamine B Dye and Crude Oil Fractions.

The release of crude oil and water-soluble dyes into our marine environment is a major global problem. An efficient semiconductor Ag-Ag3PO4 photocatalyst was synthesized using formaldehyde as a reducing agent to form surface active Ag on Ag3PO4 under microwave radiation for heating, and its potential in destroying environmental pollutants has been examined. The diffuse reflectance spectroscopy of Ag-Ag3PO4 revealed an enhanced absorption in the visible light region. The rate of photocatalytic degradation of rhodamine B by Ag-Ag3PO4 was over 4-fold compared to Ag3PO4. The potential application of Ag-Ag3PO4 in oil spill remediation was also examined through photocatalytic degradation of benzene, n-hexane, and 1:1 v/v benzene/methanol crude oil-soluble fractions. UV-vis and gas chromatography-mass spectrometry analysis of the crude oil components after visible light irradiation showed excellent degradation. The photocatalytic efficiency enhancement of Ag-Ag3PO4 is attributed to the excellent electron trapping of silver nanoparticles deposited on the surface of Ag3PO4. This work will motivate future studies to develop recyclable visible light photocatalysts for many applications.