Improved visible light photocatalytic activity of Fe, N co-doped TiO2 for degradation of o-chlorophenol in water

A nanostructured photocatalyst based on Fe, N co-doped TiO2 (Fe-y + N-x/TiO2; y = 0.5, 1, 2 and 3 %, and x = 2, 5, 10 and 13 %) was synthesized using the sol-gel method and applied for degradation of o-CP in water. The XRD, SEM analyses of prepared photocatalysts indicted the successful synthesis and doping of TiO2 with Fe and N. Results of an EIS study illustrated that the doping process in Fey + Nx/TiO2 decreased the charge transfer resistance and increased the carrier transfer rate between sample and electrolyte. UV-vis absorption spectra revealed that the optical band gap of pure TiO2, Fe-2/TiO2, N-10/TiO2, and Fe2+N10/TiO2 was obtained at 3.07, 2.98, 2.77 and 2.65 eV, respectively, indicating the doping leads to narrowing of the optical band gap and red-shifting of absorption towards the visible light region. Photodegradation studies of Fe-y+N-x/TiO2 showed that Fe2+N10/TiO2 had the optimal content of Fe and N dopants for fast degradation of o-CP aqueous solution. The complete removal of 5, 10, 50 and 100 mg/l of o-CP was obtained after 120, 200, 255 and 360 minutes of simulated sunlight irradiation, respectively. Comparison of these results with photocatalytic performance of reported systems in the literature showed the effective performance of the prepared photocatalyst for photodegradation of o-CP under simulated sunlight because of the synergistic effect of both Fe and N in the Fe-2+N-10/TiO2 nanoparticles that led to a decrease in the recombination rate of photogenerated carries and a narrowing band gap.

Automated summary

In this study, a nanostructured photocatalyst based on Fe and N co-doped TiO2 was synthesized and successfully used for the degradation of o-CP in water. The doping process was found to decrease charge transfer resistance and increase carrier transfer rate, resulting in a narrowing of the optical band gap and red-shift of absorption wavelength. Fe-2+N-10/TiO2 exhibited the best photocatalytic performance among the prepared samples, achieving complete removal of o-CP under simulated sunlight irradiation.