Enhanced photocatalytic performance of hydrothermally synthesized TiO2 nanowires for H2 production via water splitting

Abstract

The effective separation and high mobility of photogenerated charge carriers are important in order to enhance the photocatalytic activity of material. The one-dimensional nanostructures are providing the path for the photogenerated charge carriers resulting higher photocatalytic activity. Herein, highly crystalline Titanium dioxide (TiO2) nanowires (TNWs) having anatase phase were synthesized using hydrothermal method by varying the reaction time and temperatures. The synthesized TNWs were characterized using various techniques. Structural study revealed the formation of anatase TiO2 along with a minor percentage of the rutile phase. Morphological study indicates the growth of TiO2 nanowires originated from spheres-wires-flakes as a function of reaction time and temperature. FE-TEM image of TiO2 nanowires prepared at 150℃ for 72 h shows complete formation of nano-wires with 7–10 nm diameter. Photocatalytic performance of the synthesized TiO2 nanowires was investigated by observing the hydrogen (H2) generation via water splitting and degradation of aqueous methylene blue (MB) dye under a 400 W mercury vapor lamp respectively. Among the prepared samples, the TiO2 nanowires prepared at 150℃ for 48 h showed the highest H2 generation of 7464.28μmol/0.1 gm higher than the Degussa TiO2. Further, the same nanostructured TiO2 shows the 100% MB degradation within 30 min (Kapp=13.54×10−2 min−1).

Keywords

• Photocatalysis
• H2-generation
• Dye degradation
• Nanowires
• TiO2
• Hydrothermal