Effect of phosphate salts (Na3PO4, Na2HPO4, and NaH2PO4) on Ag3PO4 morphology for photocatalytic dye degradation under visible light and toxicity of the degraded dye products.

Ag3PO4 was synthesized by the pptn. method using three different types of phosphate salts (Na3PO4, Na2HPO4, and NaH2PO4) as a pptg. agent. Hydrolysis of each phosphate salt gave a specific pH that affected the purity and morphol. of the prepd. Ag3PO4. The Ag3PO4 prepd. from Na2HPO4 showed the best photocatalytic activity induced by visible light to degrade methylene blue dye. During the photocatalytic process, Ag3PO4 decompd. and produced metallic Ag, and this evidence was confirmed by the X-ray diffraction technique and XPS. The photocatalytic efficiency decreased with the no. of recycles used. This Ag3PO4 photocatalyst also degraded another cationic dye, rhodamine B, but did not degrade reactive orange, an anionic dye. The degraded products produced by the photocatalysis had lower toxicities than the untreated dyes using Chlorella vulgaris as a bioindicator. [on SciFinder(R)]