Fig. 7From: Enhanced Photoelectrochemical Activity of ZnO-Coated TiO2 Nanotubes and Its Dependence on ZnO Coating Thickness a Nyquist plots and b MottâSchottky plots of bare TiO2 NTs, 10-cycle ZnO/TiO2 NTs, and 25-cycle ZnO/TiO2 NTsBack to article page