Interaction of oxyhalide anions with Ce3+ ions and CeO2-x nanoparticles in water solutions

Cerium oxide (CeO2-x) nanoparticles are well-known for their role in catalytic removal of reactive oxygen species (including hydrogen peroxide, superoxide anions and hydroxyl radicals). In the paper the interaction between oxyhalide anions of different kinds with Ce3+ ions in CeCl3 water solutions and the same ions in cerium oxide nanoparticles was compared using Ce3+ luminescence. Addition of hypochlorite and periodate anions to water solutions leads to Ce3+ -> Ce4+ oxidation, and, so to concentration-dependent decrease of Ce3+ luminescence intensity, which is reversible for nanoceria, but not for CeCl3 water solutions. Dependence of Ce3+ luminescence on oxidant concentration and reversibility of Ce3+/Ce4+ ratio open the way to apply nanoceria for sensing and removal of oxyhalides in drinking water.