Fabrication of Highly Crystalline SnNb2O6 Shell with a Visible-Light Response on a NaNbO3 Nanowire Core

A visible-light-absorbing SnNb2O6 shell with high crystallinity was successfully fabricated on a NaNbO3 nanowire through a molten salt treatment of the NaNbO3 nanowire of the starting material with SnCl2, whereas the fabrication was not successful on the TT phase of a niobia nanowire. The difference will come from the formation processes of SnNb2O6 crystals (ion-exchange reaction vs thermally induced crystallization reaction). The core/shell nanowire obtained from NaNbO3 showed photocatalytic activity comparable to that of H-2 evolution in the presence of an electron donor, under visible-light irradiation (lambda > 420 nm), compared with the corresponding bulky counterpart.