Figure 2
From: Bandgap reduction of photocatalytic TiO2 nanotube by Cu doping

Four cases considered for the Cu-doping model. White, red and blue spheres represent Ti, O and Cu atoms, respectively. All distances are in unit of Angstrom.
From: Bandgap reduction of photocatalytic TiO2 nanotube by Cu doping

Four cases considered for the Cu-doping model. White, red and blue spheres represent Ti, O and Cu atoms, respectively. All distances are in unit of Angstrom.