Ultrasound‐assisted sol–gel synthesis of N‐<scp>TiO₂</scp>, Fe‐<scp>TiO₂</scp>, and <scp>TiO₂</scp> with application in treatment of a commercial effluent

Abstract BACKGROUND Nitrogen doped titanium dioxide (N‐TiO 2 ), iron doped titanium dioxide (Fe‐TiO 2 ), and undoped titanium dioxide (TiO 2 ) 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‐TiO 2 , Fe‐TiO 2 , and undoped TiO 2 , respectively. Field electron scanning electron microscopy (FE‐SEM) images confirmed that N‐TiO 2 is a mixture of TiO 2 microspheres and rice‐like structures whereas Fe‐TiO 2 and undoped TiO 2 were spherical. X‐ray photoelectron spectroscopy (XPS) study showed that both N‐TiO 2 and Fe‐TiO 2 exhibited minor shifts to lower binding energies when compared to the spectra of undoped TiO 2 . 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‐TiO 2 catalyst obtained using ultrasound at pH of 12 and addition of a 20 mL per L −1 dose of H 2 O 2 . CONCLUSION Doping TiO 2 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‐TiO 2 + H 2 O 2 based approach. © 2025 Society of Chemical Industry (SCI).