Band gap engineering of ceria nanostructures by incorporating nitrogen-containing heterocyclic ligands

A novel facile method to prepare ceria nanocrystals with well-defined cubic morphology and enhanced optical properties is herein disclosed. Both the decrease in the band gap and the appearance of absorption edges above 400 nm, which redound in a significant absorption of visible light, are accomplished by simply incorporating in situ different amounts of a typical chelating bidentate ligand, 1,10-phenanthroline, during the synthesis of these ceria nanocubes. Such a remarkable effect has been tentatively connected with the ability of this nitrogen-containing heterocyclic compound to coordinate Ce3+ cations from the ceria precursor salt, thus yielding intermediate N 2p states along the band gap of the oxide.