Figure 4From: Self-organized vanadium and nitrogen co-doped titania nanotube arrays with enhanced photocatalytic reduction of CO2 into CH4UV-vis spectra and energy of absorbed light plot. UV-vis diffuse reflectance spectra (a) of N-TiO2 and V, N co-doped TiO2 nanotube arrays. The (αh v) 1/2 vs. energy of absorbed light plot (b) for band gap calculation of all samples.Back to article page