Özdokur, Kemal Volkan; Bozkurt Çırak, Burcu; Eden, Çiğdem; Ahmad Boda, Muzaffar; Çırak, Çağrı

TiO2 nanotube/graphene-like carbon nitride (g-C3N4) composite structure was fabricated by a novel synthesis approach. Amorphous TiO2 nanotube arrays was synthesized by anodization. Afterward, g-C3N4 structures were decorated on the amorphous TiO2 nanotube arrays by using thermal polymerization process while anatase phase transformation of TiO2 in progress for the first time. The nanocomposite electrodes were further used for photo-electrochemical degradation of Rhodamine B dye. The homogenous surface morphology, higher crystallinity and more efficient photo-electrochemical performance were obtained by TiO2 nanotube/g-C3N4 composite structure due to better electrical contact and electron transportation by described synthesis approach.

Bozkurt Çırak, Burcu; Eden, Çiğdem; Erdoğan, Yaşar; Demir, Zeynep; Özdokur, K. Volkan; Caglar, Bulent; Morkoç Karadeniz, Sibel; Kılınç, Tuba; Ercan Ekinci, Ali; Çırak, Çağrı

In this study, TiO2/ZnO hybrid nanocomposites (TZ) were fabricated by two step synthesis route for potential applications as photoanode in dye sensitized solar cells (DSSC). Titania nanotubes were grown on titanium sheets by electrochemical oxidation. ZnO nanorods were decorated with hydrothermal method by equimolar (0.1 M) precursors on TiO2 nanotubes. Hydrothermal temperatures values were changed to find the optimal ZnO decoration density to increase photo conversion efficiency. The characterization of the photoanodes was made using FE-SEM, XRD and XPS techniques. The results show that hydrothermal reaction temperature can dramatically enhance the light harvesting performance of TZ photoanodes. The photo conversation efficiency of DSSC by TZ photoanode was reached 1.67 % for hydrothermal temperature of 130 °C which is twofold higher than that of DSSC by TiO2 nanotubes (0.81 %). The improvement in photo conversation conversion efficiency can be assigned to synergetic effect in TZ photoanode, lower recombination rate and charge transfer resistance.