PHYSICOCHEMICAL AND SENSORY PROPERTIES OF Y-TiO2 FILMS

• Datum: 2026
• Hauptverfasser: Medyk, Iryna, Vorobets, Vera, Kolbasov, Gennadii, Karpenko, Sergey, Oblovatna, Svetlana
• Format: Artikel
• Sprache: Englisch
• Veröffentlicht: V.I.Vernadsky Institute of General and Inorganic Chemistry 2026
• Online Zugang: https://ucj.org.ua/index.php/journal/article/view/773
• Назва журналу: Ukrainian Chemistry Journal

The study focuses on the investigation of the effect of yttrium ion modification on the structural, morphological, photoelectroche­mical, electrocatalytic, and sensing properties of nanostructured titanium dioxide (TiO2) films. The Y-TiO2 films, with yttrium concentrations ranging from 0.5 to 5.0 at.%, were synthesized using a sol-gel method by annealing at 500 °C. Characterization was performed using XRD, photocurrent spectroscopy, and voltammetry. XRD analysis revealed that all synthesized samples maintained a single-phase anatase structure. It was established that yttrium acts as a structural stabilizer, effectively inhibiting crystallite growth; the average crystallite size decreased from 14.0–10.0 nm. However, increasing yttrium content led to partial amorphization of the TiO2. The photoelectrochemical results demons­trated a substantial increase in the photocurrent quantum yield and a bathochromic shift of the spectral maxima for modified films compared to pristine TiO2. The optimal yttrium concentration for maximizing photosensitivity was found to be 2.0 at.%. This enhancement is attributed to the creation of defect states and active centers that facilitate charge separation and extend the absorption range into the visible spectrum. Electrocatalytic investigations into the oxy­gen reduction reaction (ORR) in 0.9% NaCl solution showed that 1% Y-TiO2 electrodes exhibit the highest activity, characterized by a shift in the half-wave potential of oxygen reduction toward the anodic region and an expanded dynamic range. Higher yttrium concentrations led to a decrease in ORR activity, likely due to the screening of active sites by the inactive amorphous phase. The sensory properties were evaluated using anodic stripping voltammetry for the detection of lead ions (Pb2+) in liquids. The 1% Y-TiO2 electrodes demonstrated a linear response in the concentration range of 0.1–3.0 mg/L with a sensitivity of 0.01 mg∙L-1.