Shell deposition-induced vertically aligned core-shell arrays of W18O49/V2O5 nanorods

A novel heterostructure array of W18O49/V2O5 core-shell nanorods with high alignment and uniform shell layer is prepared with the induction of shell layer deposition to roughly aligned W18O49 nanorods. The roughly aligned W18O49 nanorods with diameter of about 20 nm are first grown via in-situ thermal oxidation of sputtered W film. After uniform sputtering-deposition and annealing of polycrystalline shell layer of V2O5, the formed W18O49/V2O5 core-shell nanorods array exhibits an interesting improvement in alignment. A highly ordered array of heteronanorods is achieved when the V2O5-shell is about 20 nm in thickness. The possible mechanism of alignment due to shell deposition is suggested. This kind of core-shell heteronanorods with highly aligned geometrical configuration and uniform coating will be important for applications of one-dimensional (1D) heterostructures in nanodevices.