fig2
Figure 2. (A) Schematic illustration of the electronic band structure; (B) The Mott–Schottky analysis of TiO2 and Cu/TiO2; (C) The photocurrent and (D) the electrochemical impedance spectra for TiO2 and Cu/TiO2. The inset shows the equivalent circuit, consisting of R1 (solution resistance), C1 (constant phase element), and R2 (CTR). CTR: Charge transfer resistance.
