Silver vanadates with light absorption properties in the visible region were successfully prepared by a low temperature pathway (not exceeding 110 degrees C) using an optimized microemulsion methodology. The resulting materials were evaluated as photocatalysts in Rhodamine B photodegradation and characterized before and after reaction. The silver vanadates displayed silver metallic nanoparticles decorating the surface. The as-prepared Ag3VO4 catalyst was the most active. Nevertheless, this silver vanadate suffered important changes during reaction. The initial structure evolves yielding a silver pyrovanadate, Ag4-V2O7, with a concomitant increase of the number and size of the silver metallic nanoparticles. The synergy between these Ag particles and the photoactivity of the Ag4V2O7 phase seems responsible of the high photoactivity of this material. (C) 2012 Elsevier B.V. All rights reserved.