Construction of rGO/Fe3O4/Ag3PO4 multifunctional composite as recyclable adsorbent and photocatalysts towards the mixture of dyes in water under visible light irradiation

In this work, multifunctional composites of rGO/Fe3O4/Ag3PO4, i.e. Fe3O4 nanoparticles (similar to 300 nm in size) and Ag3PO4 nanoparticles(similar to 40 nm in size) loaded on the carbon basal planes of reduced graphene oxide, are synthesized for the recyclable adsorbent and photodegradation of the MB-RhB mixture solution under visible light irradiation. Results prove that the absorption performance for single dye is different from that in the mixture solution, and that the prepared rGO/Fe3O4/Ag3PO4 composite exhibits a higher absorption and higher degradation ability for MB than RhB. Further study shows that MB and RhB in the mixture solution have a different pH-dependent photocatalytic degradation performance. Regeneration using H2O2 fully restored the photoactivity of the used rGO/Fe3O4/Ag3PO4 composite isolated from the reaction solution by an external magnet, verifying its potential application in water purification.