Tailoring the Morphology and Electrochemical Behavior of TiO₂ Powders via Surfactant-Assisted Synthesis by a Modified...

Searching for sustainable alternatives to environmental challenges has driven significant interest in metal oxides, particularly TiO₂, due to its versatility in energy conversion, pollutant adsorption, and electrochemical applications. TiO₂ powders were synthesized via a modified Pechini method, comparing the conventional route with the use of the Tween-80 surfactant as a structure-directing agent. Structural, morphological, and electrochemical characterizations were performed to assess the impact of the synthesis on material performance. Thermogravimetric analysis (TG) revealed distinct decomposition profiles, with the Tween-based precursor exhibiting enhanced thermal stability. X-ray diffraction confirmed the formation of anatase-rutile structures, with Tween-80 favoring a higher anatase content (74.3% anatase phase). Scanning electron microscopy (SEM) and specific surface area (S_BET) measurements demonstrated that Tween-80 promoted a more porous and fragmented morphology, leading to a 21-fold increase in specific surface area. ζ potential and XRD-Rietveld analysis further elucidated the influence of the organic precursor on the surface charge and crystallite size. Electrochemical impedance spectroscopy (EIS) showed a significant reduction in charge transfer resistance (65.8 kΩ), compared to that of ethylene glycol-based films (943 kΩ), while cyclic voltammetry (CV) in the presence of methylene blue indicated improved redox activity, enhancing the applicability of this TiO₂ powder in several areas.