This study presents a comprehensive comparative investigation of synthesized titanium dioxide (TiO2) via the sol-gel method and commercially available TiO2_P25 for the photocatalytic degradation of methylene blue (MB) under UV irradiation. Physicochemical characterization using FTIR, XRD, Raman Spectroscopy, UV–Vis DRS, SEM, and TEM revealed comparable phase composition (anatase) and band gap energy (Eg=3.3 eV) for both materials. Synthesized TiO2 exhibited smaller (10–30 nm) and more polydisperse nanoparticles with a tendency for agglomeration compared to the larger (30–50 nm), more uniform TiO2-P25. Photocatalytic activity assessment demonstrated that synthesized TiO2 achieved a significantly higher MB degradation efficiency (88.48 % at 120 min) compared to TiO2_P25 (50.78 % at 120 min), with pseudo-first-order kinetic analysis yielding a higher rate constant for synthesized TiO2 (k = 0.0145min−1) than TiO2_P25 (k = 0.0046min−1). Reactive oxygen species (ROS) scavenging experiments indicated that both hydroxyl (•OH) and superoxide (•O2−​) radicals were the primary active species in the degradation process. The optimal degradation efficiency for synthesized TiO2 was observed at a near-neutral pH (6.8), and the presence of interfering anions (Cl−, NO3−, CO32−) negatively impacted the degradation rate, with carbonate ion showing the most significant inhibition. Reusability studies confirmed the good stability of synthesized TiO2 over 4 cycles with a slight decrease in efficiency, corroborated by consistent XRD patterns. This study highlights the superior photocatalytic performance of the synthesized TiO2 under the tested conditions and provides valuable insights into the structure-activity relationships for efficient dye degradation. © 2025 Elsevier B.V.