A magnetic vanadium oxide nanoparticles supported on spinel copper ferrite (CuFe 2 O 4 -VO x ) are prepared, characterized, and examined for the peroxymonosulfate (PMS) activation to degrade Rhodamine B (RhB) in water solution. Interestingly, the results show that despite the inability of mixture of copper ferrite and vanadium oxides nanoparticles to the effective RhB decomposition, the prepared catalyst exhibits an excellent catalytic ability toward RhB oxidation. The influence of vital parameters, such as temperature, PMS concentration, catalyst loading, and initial pH are discussed comprehensively. The kinetic studies demonstrate that the pseudo-first-order model is well fitted for RhB degradation in CuFe 2 O 4 -VO x /PMS system and the activation energy is estimated at 19.60 kJ mol À1 . Furthermore, it is found out that the concentration of leached metal ions in solution is negligible and PMS activation is done mainly on the surface of the catalyst. A probable mechanism of PMS activation over RhB degradation is proposed based on the results of free radical quenching studies and X-ray photoelectron spectroscopy (XPS) analysis. Radical quenching experiments using various scavengers suggest SO 4•À as a main reactive species in the degradation.