Two-step chemical vapor deposition (CVD) in combination with metal-catalyzed vapor-liquid-solid (VLS) growth mechanism was used as a new approach to synthesize and modify the morphology of SnO2-TiO2core-shell nanowires. SnO2nanowires were grown by decomposition of Sn(OtBu)4precursor on Au-coated Al2O3substrates followed by the growth of a TiO2overlayer by the CVD of Ti(OiPr)4. Structural characterization of SnO2-TiO2heterostructures by X-ray diffraction and high-resolution TEM revealed the formation of mixed SnxTi1–xO2compositions (x = 0.857-1.0) at the SnO2-TiO2phase boundaries, where x depended on the annealing temperatures. The observed oriented attachment of TiO2nanoclusters on single crystal SnO2core was possibly due to low lattice mismatch. The photocatalytic studies suggested an enhanced activity in SnO2-TiO2heterostructures due to higher surface area and change in the electronic structures caused by Sn4+doping in TiO2.
Journal of Physical Chemistry C , 2011, 115 (35), 17265-17269.