Hydrothermal synthesis of WO3·0.5H2O microtubes with excellent photocatalytic properties

Pyrochlore WO3 microtubes were synthesized via a hydrothermal method for the first time. In this process, thiourea was employed to overcome the hydrogen bonds on the rim of WO3·0.5H2O and hydroxylamine hydrochloride was used as a viscosity regulator. Field-emission scanning electron microscopy and high-resolution transmission electron microscopy observations revealed that large amounts of uniform single-crystal WO3·0.5H2O microtubes with diameters ranging from 100 to 300 nm and length of tens of micrometers were obtained. The thickness of the tube wall was about 40 nm. A possible rolling mechanism was proposed to explain the formation of the tubular structures, and the influence of thiourea and hydroxylamine hydrochloride on the uniform tubular morphology was discussed. The WO3·0.5H2O microtubes showed excellent photocatalytic activity toward the degradation of organic molecules such as RhB, which may find potential applications in the fields of photocatalysts, sensors and transistors.