Photocatalysis of Cr- and Fe-Doped CeO 2 Nanoparticles to Selective Oxidation of 5-Hydroxymethylfurfural.

Oxygen vacancies ( V o ) present in CeO 2 nanoparticles (NPs) can effectively boost their photocatalytic activity under ultraviolet (UV) light. To improve photocatalytic performance, Cr- and Fe-doped CeO 2 NPs with increased V o were prepared using a simple method of doping Cr and Fe ions into CeO 2 NPs, which was confirmed by an in-depth analysis of the structural and electronic changes. Through photocatalytic degradation (PCD) experiments with 5-hydroxymethylfurfural (HMF), we found that the PCD rates of the two doped CeO 2 NPs were faster than that of the CeO 2 NPs. In addition, the conversion of HMF to 2,5-furandicarboxylic acid (FDCA) using the doped CeO 2 NPs occurred only through the mechanism of the selective oxidation to 5-hydroxymethyl-2-furancarboxylic acid (HMFCA), exhibiting better efficiency than using CeO 2 NPs.