Intensification of Rhodamine B photodegradation using TiO₂ nanocatalyst synthesized via non-conventional sol-gel method

This study investigates the synthesis, characterization, and photocatalytic activity of TiO 2 nanoparticles prepared via a non-conventional sol-gel method, calcined at 400, 600, and 800°C. A comprehensive analysis was performed, using XRD, TG/DSC, FTIR-ATR, and SEM/EDX techniques. The BET surface area, pH pzc , and the band gap of the samples were also measured. The photocatalytic degradation of Rhodamine B (RhB) was investigated under UV irradiation, with a focus on the effects of operational parameters, including initial dye concentration and photocatalyst loading, for each calcined sample. A detailed investigation of the effects of pH and irradiation wavelength on the sample calcined at 400 °C was carried out. The photocatalytic performance of TiO 2 catalysts was benchmarked against the commercial Degussa P-25. The Rhodamine B degradation efficiencies reached 96.11 %, 93.37 %, and 81.25 % for TiO₂ samples calcined at 400, 600, and 800 °C, respectively, whereas Degussa P-25 achieved a degradation efficiency of 92.07 % after 90 min of UV irradiation. The kinetic analysis indicated that the pseudo-first-order model provided a better fit than the pseudo-second-order. The Langmuir–Hinshelwood approach showed a good linear fit with a regression coefficient of 0.99. These findings highlight the effect of TiO 2 properties and photocatalytic process conditions on enhancing the photodegradation of persistent organic pollutants in sustainable water treatment applications. • The TiO₂ catalyst synthesized via a non-conventional sol–gel route. • TiO₂ calcined at 400 °C showed higher RhB degradation than commercial P25. • Calcination affected structural, textural, and morphological features of TiO₂. • Photocatalytic efficiency influenced by TiO 2 physicochemical properties. • Photodegradation followed pseudo-first-order and L–H kinetic models.