CdO-Intercalated TiO2 Nanosphere-Clusters: Synthesis and Electrical, Optical and Photocatalytic Properties

Nanocrystalline TiO2, owing to its optical and electrical properties and chemical stability, is a technologically and industrially important semiconductor material. Modification of its optoelectronic characteristics by implanting CdO nanocore enables to retain its non-toxicity as well as stability and this cannot be achieved by Cd2+-doping or depositing CdO. CdO-intercalated TiO2 forms type III heterojunction and its synthesis and optoelectronic properties are unexplored. Nanocrystalline CdO was obtained by precipitation method and CdO-intercalated anatase TiO2 nanosphere-clusters synthesized by sol-gel technique. The scanning electron micrographs reveal the size of nanospheres forming the clusters as 115-165 nm. The energy dispersive X-ray spectrum confirms the presence of the constituent elements. Selected area electron diffractometry along with transmission electron microscopy shows intercalation of CdO nanocore in TiO2 anatase lattice. While the charge transfer resistance of the synthesized sample is larger than that of pristine TiO2 the band gap of the obtained nanospheres does not differ from that of pristine TiO2. However, the intercalation suppresses the deep level emission. The synthesized nanosphere-cluster is an efficient photocatalyst. The photocatalytic activities of CdO-intercalated TiO2 and pristine TiO2 have been analyzed in terms of their optical and electrical properties.