ZnO–TiO2 nanocomposites formed under submerged DC arc discharge: preparation, characterization and photocatalytic properties

Abstract

A rutile TiO2 (α-TiO2) and hexagonal wurtzite ZnO nanocomposite was directly and synchronously synthesized via arc discharge method submerged in de-ionized water. In correlation with the detailed characterization of the morphology, and crystalline structure of the prepared ZnO–TiO2 nanocomposites, the UV–visible and photoluminescence properties were studied. X-ray diffraction and transmission electron microscopy investigations revealed the co-existence of α-TiO2 and hexagonal wurtzite ZnO phases with the ZnO and α-TiO2 nanoparticles are in nanorod and nanospheres morphologies, respectively. The diameters of the synthesized nanocomposite particles are in the range of 5–70 nm. Interestingly, the as-prepared ZnO–TiO2 nanocomposite shows better photocatalytic activity for photodegradation of the methylene blue dye than both of pure ZnO and TiO2 nanocatalyts. This work would explore feasible routes to synthesize efficient metal or/and metal oxide nanocomposites for degrading organic pollutants, gas sensing or other related applications.