Effects of nitrogen content in monocrystalline nano-CeO2 on the degradation of dye in indoor lighting

Azo dyes are an abundant class of synthetic dyes, however their complex structure makes them difficult to biologically degrade. We sought to degrade acid orange 7 (AO7) using nitrogen-doped nano-CeO2, which is a promising alternative photocatalyst to nitrogen-doped TiO2. Nitrogen-doped monocrystalline CeO2 nanoparticles with various nitrogen contents were synthesized solvothermally at 120 ̊C from Ce(NO3)3·6H2O, triethanolamine, and ethanol. The CeO2 monocrystals were between 7 and 8 nm in diameter. Nitrogen was shown to be incorporated into CeO2 lattice from the results of the lattice parameter calculations, X-ray photoelectron spectroscopy analysis and elemental analysis. The degradation of AO7 in water was investigated using a domestic 10 W compact fluorescent lamp. The degradation efficiency of AO7 by monocrystalline CeO2 increased with increasing nitrogen content, reaching 97.6% for the sample with a N:Ce molar ratio of 0.3.