389505.fig.001a
(a)
389505.fig.001b
(b)
389505.fig.001c
(c)
389505.fig.001d
(d)
Figure 1: SEM (a) and TEM (c) images pristine hollow Nb-TiO2 nanostructures. SEM (b) and TEM (d) images Pt nanoparticles deposited on hollow Nb-TiO2 nanostructures.