Mo-substituted CeVO4 system: solid solution formation and implications on sorption behaviour

Synthesis of Mo-substituted CeVO4 systems by facile co-precipitation process is reported wherein an upper solubility limit of 40 mol% Mo was obtained retaining the tetragonal structure. Solid solution formation was investigated by X-ray diffraction, X-ray fluorescence and Raman spectroscopy and XPS. Introduction of Mo into the anionic framework yielded hierarchical mesoporous structures with substantial increase in surface area from 76 to 147 m2/g as exhibited by TEM and BET analysis. Complete uptake of Pb2+ ions from aqueous solutions was shown by both CeVO4 and Mo-CeVO4 with sorption capacity of 100 mg/g. In addition, the presence of Mo in CeVO4 depicted five times faster and superior kinetics than pure CeVO4. Various isotherms have been used to model the data. This study not only unravels the structural aspects of Mo-substituted CeVO4 system but also discusses new promising sorbents for toxic Pb2+ ions obtained by simple synthetic route.