Synthesis of TiO2 nanowires and their photocatalytic activity for hydrogen evolution

TiO2 nanowires (TiO2 NWs) were synthesized through the one step hydrothermal process in 10 M NaOH (aq.) at 150 °C for 72 h followed by post-heat-treatment at 300–1000 °C for 2 h. SEM and XRD measurements revealed that as-synthesized TiO2 NWs were transformed into TiO2 (B) structure with maintaining 1D morphology at 300–400 °C and further transformed into anatase structure at 500–800 °C. At 900–1000 °C, they partly transformed into rod-shaped rutile structure. The photocatalytic activity of prepared samples was evaluated with photocatalytic H2 evolution from aqueous methanol solution. The results indicated that the TiO2 NWs treated at appropriate post-heat-treatment temperature exhibited higher photocatalytic H2 evolution than that of starting TiO2 powder (Degussa P-25).