Characterizations and photocatalytic activity of ceria nanoparticles synthesized in KCl–LiCl/KOH–NaOH molten flux from different precursors

Molten salts synthesis (MSS) is a simple and potential technique for ceria nanoparticles (NPs) production, but the relevant effects of salt medium and cerium precursor on the synthesized ceria NPs need further attention. In the present work, we investigated the influences of frequently employed KCl–LiCl and KOH–NaOH molten flux and typical inorganic cerium precursors on the characterizations and photocatalytic property of ceria NPs. Results show that the CeO 2 NPs obtained in molten KOH–NaOH flux have smaller particle/crystal sizes but more serious agglomeration than that from KCl–LiCl flux. UV–Vis DRS spectra reveal that the ceria synthesized in molten hydroxides from the cerium nitrate precursor has the narrowest band gap of 2.87 eV in studied ceria samples. The ceria NPs obtained from KCl–LiCl flux have wider band gaps of 3.15–3.29 eV and faster recombination rates of photo-generated e − and h + . It was found that the ceria NPs obtained in molten KCl–LiCl salt show better photocatalytic activities for methylene blue (MB) degradation and may be due to the uniform size distribution and well-dispersed particles.