Affiliation:
1. Department of Chemistry Faculty of Science and Arts University of Afyon Kocatepe 03200 Afyonkarahisar Türkiye
2. Department of Biomedical Engineering Faculty of Engineering University of Afyon Kocatepe 03200 Afyonkarahisar Türkiye
3. Schiavello-Grillone Photocatalysis Group Engineering Department University of Palermo 90128 Palermo Italy
4. Department of Metallurgy and Materials Engineering Faculty of Engineering Dokuz Eylül University Tınaztepe Campus Buca 35397 İzmir Türkiye
5. Center of Electronic Materials Production and Application (EMUM) Dokuz Eylül University Tınaztepe Campus Buca 35397 İzmir Türkiye
Abstract
AbstractNanotube/nanowire structured TiO2 samples on Ti plates were prepared by anodic oxidation in aqueous, glycerol or ethylene glycol medium under different experimental conditions and characterized by XRD, SEM‐EDX, electrochemical methods (photocurrent profiles and electrochemical impedance spectroscopy). The nanostructured TiO2 was built on relatively large Ti plates, and consequently, in some preparation conditions, different morphologic properties were observed in the underside and upside zones of the electrodes, especially in ethylene glycol medium. The electrodes were tested for selective photoelectrocatalytic oxidation of 3‐methylpyridine to 3‐pyridinemethanol, 3‐pyridinemethanal and vitamin B3 in water under UVA irradiation. The best performance was found with the electrode prepared in ethylene glycol/water/NH4F (98/2/0.3 w/w) medium at 36 V potential for 3 h, while the worst was that prepared in aqueous medium which showed the shortest nanostructure length. Unlike photoelectrocatalysis and photocatalysis, no aromatic alcohol/carbonyl products were obtained in electrocatalytic and photolytic experiments. The selectivity values of the products were similar for the various electrodes, while the morphology of the nanotubes/nanowires and their quantity which affects the total active surface area were essential for the substrate conversion. The results also show that the photocurrent intensity, XRD peak intensity, and electrical conductivity are correlated with photoelectrocatalytic activity of the Ti/TiO2 electrodes.