Microwave-Assisted Hydrothermal Synthesis of N-TiO2 Nanophotocatalyst Used in Removal of Acid Orange 7 from Wastewater

Photocatalytic wastewater treatment as an important member of advanced oxidation processes with a high energy efficiency plays important role in wastewater treatment. This method is known as an energy efficient method because of solar light utilization availability. In this work, TiO2 nanophotocatalyst has been synthesized using titanium (IV) butoxide as a Ti precursor. Then, the nitrogen doping was considered to activate the photocatalytic ability in the visible part of the light spectrum. N-TiO2 nanophotocatalysts were synthesized using a hybrid method of hydrothermalmicrowave. The analyses of XRD, FESEM, BET, EDX and UV-vis spectroscopy were carried out to evaluate the physicochemical and optical properties of the catalysts. The XRD analysis has confirmed the successful synthesis of the TiO2 with anatase crystalline phase. FESEM images have confirmed the nano-sized structure of the catalysts. The BET surface area coincided the FESEM results by representation of surface area enhancement after doping with nitrogen. EDX has verified the presence of nitrogen in the sample and demonstrated uniform dispersion and no agglomeration of Nitrogen presented on the catalyst surface. The photocatalytic degradation of dye from the synthetic wastewater was carried out resulting the highest photocatalytic activity for N-TiO2 in comparison to undoped samples. The experiment resulted 90 percent of degradation after 140 min while undoped TiO2 represented just 52 percent of degradation. Also, to have a better comparison, the industrial photocatalyst P25 was used in the same experiment time and operational conditions. The results depicted higher photocatalytic activity for hydrothermal-microwave synthesis of TiO2 compared to industrial TiO2 with 15 percent higher degradation.