Visible-Light Photocatalytic Activity of N-Doped TiO₂ Nanotube Arrays on Acephate Degradation

Figure 5

UV-vis absorption spectra of different samples, (a) pure TiO₂ nanotube arrays annealed at 400°C and N-TiO₂ nanotube arrays annealed at (b) 400°C and (c) 500°C.