ZnO/TiO2 photocatalytic nanocomposite for dye and bacteria removal in wastewater

Abstract

This study investigates ZnO/TiO _2 nanocomposites synthesized by the sol–gel method for their potential application in textile wastewater treatment. The physicochemical properties of these materials were comprehensively characterized using various analytical techniques, including transmission electron microscopy (TEM), x-ray diffraction (XRD) analysis, x-ray fluorescence (XRF) spectroscopy, Brunauer–Emmett–Teller (BET) surface area analysis, and UV–visible (UV-Vis) spectroscopy. XRD and XRF analyses confirmed the formation of a ZnO/TiO _2 heterostructure. TEM images revealed a quasi-spherical morphology with slight agglomeration. The ZnO/TiO _2 nanocomposite with a 1:5 molar ratio of Zn(II):Ti(IV) showed the highest BET surface area (91.345 m ^2 g ^−1 ) and the narrowest band gap (Eg = 3.06 eV). This composite demonstrated efficient degradation of methylene blue dye under sunlight irradiation and exhibited 100% antibacterial activity against S. typhi and S. aureus at concentrations ≥5 mg ml ^−1 , indicating its potential for treating textile wastewater.

Keywords

• photocatalysis
• antibacterial efficiency
• ZnO/TiO2 nanocomposite
• sol-gel
• heterostructure
• band gap