Nitrogen doped TiO2 nanotube arrays with high photoelectrochemical activity for photocatalytic applications

Photocurrent spectra of as-prepared TiO2 nanotube arrays and N-doped TiO2 nanotube arrays. A pure TiO2 nanotube arrays without annealing, b pure TiO2 nanotube arrays annealed at 500 ̊C; N-doped TiO2 nanotube arrays annealed at different temperatures, c 300 ̊C, d 400 ̊C, e 500 ̊C, f 600 ̊C, g 700 ̊C. The inset shows the photocurrent versus annealing temperature of N-doped TiO2 nanotube arrays.