Ultrasound-assisted sol–gel synthesis of N-TiO2, Fe-TiO2, and TiO2 with application in treatment of a commercial effluent

Abstract

BACKGROUND

Nitrogen doped titanium dioxide (N-TiO₂), iron doped titanium dioxide (Fe-TiO₂), and undoped titanium dioxide (TiO₂) nanocatalysts were synthesized using sol–gel method aided with ultrasound (US). The effects of duty cycle, US-power, and US irradiation time on catalyst characteristics were investigated so as to establish the best synthesis conditions.

RESULTS

The optimum parameters for minimum mean size of catalyst particles were 60% duty cycle, 100 W power, and 20 min as irradiation time. X-Ray diffraction (XRD) analysis revealed that the primary phase of all nanocatalysts was anatase with crystallite size as 46.29 nm, 54.32 nm, and 56.17 nm for N-TiO₂, Fe-TiO₂, and undoped TiO₂, respectively. Field electron scanning electron microscopy (FE-SEM) images confirmed that N-TiO₂ is a mixture of TiO₂ microspheres and rice-like structures whereas Fe-TiO₂ and undoped TiO₂ were spherical. X-ray photoelectron spectroscopy (XPS) study showed that both N-TiO₂ and Fe-TiO₂ exhibited minor shifts to lower binding energies when compared to the spectra of undoped TiO₂. The application studies for obtained catalysts using simple ultrasonic horn and disc horn coupled with oxidants revealed best results (51.67% reduction in COD) using disc horn for N-TiO₂ catalyst obtained using ultrasound at pH of 12 and addition of a 20 mL per L⁻¹ dose of H₂O₂.

CONCLUSION

Doping TiO₂ with metal and non-metal ions coupled with using ultrasound in synthesis improved the catalytic activity with maximum COD reduction of commercial effluent obtained for disk horn + N-TiO₂ + H₂O₂ based approach. © 2025 Society of Chemical Industry (SCI).