Comment on: "Structural, morphological and optical properties of shuttle-like CeO2 synthesized by a facile hydrothermal method," by Li et al., J. Alloys Comp., 722 (2017) 489

We comment on the interpretation put forward by Li et al. that their ceria particles involve sizable amounts of Ce ions. We propose that these nanoparticles consist of virtually pure ceria, and that they contain carbonated and hydrated species.