The Synthesis and band gap changes induced by the doping with rare-earth ions in nano-SnO2

A series of pure and Eu-doped (5%, molar ratio) nano-SnO2 are prepared by a hydrothermal methods. The crystalline phase, morphologies and band gap of doped and pure samples are systematically studied. The nanosheets, nanorods and nanospheres are obtained by different ways for a further investigation. Doping Eu3+ in nano-SnO2 could change the particle size, crystallinity, morphology, and band gap obviously. The doped samples present the trend of agglomerate, but the morphology is very similar among the samples, which are doped with different kinds of the rare-earth ions. It is interesting that the band gap of SnO2 decreases as Eu3+ ions are added which is helpful in the design of functional nanomaterials such as optical, electrical materials.