Electrochemical Study and Synthesis of Highly-ordered TiO2 Nanorods Arrays on 3D Graphene Oxide Framework as Photocatalyst for Acid Orange 7 Degradation

The current research focused on the hydrothermal synthesis of highly-ordered TiO2 nanorods arrays on a 3D graphene oxide framework (TiO2 NRs/3D-GO) and the photocatalytic performance of the TiO2 NRs/3D-GO in the decolorization of Acid orange 7 (AO7) from textile wastewater in the presence of UV light. The results of structural investigations revealed that TiO2 NRs arrays were anchored on wrinkles of 3D-GO nanosheets, resulting in a porous surface with multiple active sites. Optical tests revealed that the band gap values of TiO2 NRs and TiO2 NRs/3D-GO were 3.11 and 3.09 eV, respectively, and that the addition of GO to TiO2 resulted in a noticeable increase in light absorption and made photo-excitation of charge carriers with low energy easier. In comparison to TiO2 NRs, EIS studies showed that TiO2 NRs/3D-GO had a higher charge carrier transfer rate and lower charge recombination. Results of photocatalytic analyses demonstrated that the total decolorization of 100 ml of 150 mg/l AO7 had been acquired after 160 and 140 minutes of UV light illumination for TiO2 NRs and TiO2 NRs/3D-GO, respectively, which revealed the efficient photocatalytic activity of TiO2 NRs/3D-GO compared to reported photocatalysts in the literature for degradation of AO7 because of the synergetic effect of 3D-GO and TiO2 NRs, and efficient separation of the electron-hole pairs due to the formation of chemical bonding as an intermediate band in the energy band gap of TiO2 NRs/3D-GO. Furthermore, the results showed that both TiO2 NRs and TiO2 NRs/3D-GO had the potential to photodegrade AO7 from textile effluent.