Enhancing photo-generated carriers transfer of K-C3N4/UiO-66-NH2 with Er doping for efficient photocatalytic oxidation of furfural to furoic acid

Biomass derived platform molecules, such as furfural, are abundant and renewable feedstock for valuable chemical’s production. It is critical to fabricate high efficient photocatalysts for selective oxidation under visible light. The Er@K-C3N4/UiO-66-NH2 catalyst was synthesized using a straight-forward hydrothermal technique, and exhibited exceptional efficiency in the photocatalytic oxidation of furfural to furoic acid. The catalyst was thoroughly characterized, confirming the band gap width of Er@K-C3N4/UiO-66-NH2 was adjusted to effectively. Upon the optimized reaction conditions, the conversion rate of furfural reached 89.3%, with a corresponding yield of furoic acid at 79.8%. The primary reactive oxygen species was identified as •O2- from ESR spectra and scavenger tests. The incorporation of Er and K into the catalyst enhanced the photo-generated carriers transfer rate, hence increasing the separating efficiency of photogenerated electron-hole pairs. This study expands the potential applications of rare earth elements doped g-C3N4 in the photocatalytic selective oxidation of furfurans.