Fig. 9From: Enhanced Photoelectrochemical Activity of ZnO-Coated TiO2 Nanotubes and Its Dependence on ZnO Coating ThicknessTransient PC densities of bare TiO2 NTs (1), 10-cycle ZnO/TiO2 NTs (2), and 25-cycle (3) ZnO/TiO2 NTs under illumination of light with wavelength cutoffs of 380 nm (a) and 420 nm (b)Back to article page