PHOTOCATALYTIC DEGRADATION OF NITRO COMPOUNDS IN WASTEWATER USING MODIFIED TIO₂ NANOCOMPOSITES

Abstract

Background: The environment pollution derived from the presence of nitro compounds in the wastewater has become an important fact by the aquatic toxicity and persistence in the ecosystem. Photo-degradation using titanium dioxide (TiO₂), in particular, has appeared as a promising technology for their abatement. However, the poor efficiency of TiO₂ under visible light requires modifications including doping with other elements to improve its photocatalytic behavior. Objectives: The objective of this study was the photocatalytic degradation of nitro compounds from wastewater using the modified TiO₂ nanocomposites under visible light radiation, namely nitrogen and iron codoped TiO₂. Method: Nitrogen and iron-doped TiO₂ was prepared to improve the photo-catalytic activity of TiO₂. The nanocomposites were systematically characterized by X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy and surface area adsorption. The photocatalytic decomposition of nitrobenzene was performed with the visible light irradiation. Results: The photo-catalytic activity of the composite Fe-N co-doped TiO2 was significantly higher, with 94% of degradation of nitrobenzene within 60 min. Dopingacticity of narrowing the band gap and improving charge carrier abrics and consequently enhanced degradation capability with respect to undoped and singly TiO₂ samples. Conclusion: Nitrogen and iron co-doped TiO₂ considerably enhances its photocatalytic degradation performance under visible light. This modifying strategy is of great application potential into nitro compounds wastewater treatment, having beneficial environmental effect.