Effect of hydrogen treatment on the photocatalytic activity of tungsten oxide nanopowders

Abstract

The results on the synthesis and study of the properties of tungsten oxide nanopowders WO3 obtained by the hydrothermal method is presented in this work. The structural features of the synthesized WO3 nanopowders were studied using X-ray phase analysis and Raman spectroscopy. The final WO3 nanopowders have a monoclinic modification of tungsten oxide. The data on the morphology of the synthesized samples obtained by scanning electron microscopy. The samples have a rectangular shape with a smooth surface in the form of nanoplates with sizes in the range of 50-150 nm. Moreover, the photocatalytic properties of nanopowders were studied for as photocatalysts for water treatment application. A significant photocatalytic activity of the synthesized materials was found during the decomposition of the test substance of the dye rhodamine B under ultraviolet illumination. A method of heat treatment of tungsten oxide nanopowders in a hydrogen atmosphere has been developed to introduce oxygen vacancies. As a result, tungsten oxide nanopowders of non-stoichiometric composition were obtained. Comparative studies on the effects of hydrogen heat treatment on photocatalytic activity have been carried out. The photocatalytic activity of the starting WO3 oxide after heat treatment in a hydrogen atmosphere at 400 °C more than doubled.

Keywords

• photocatalysis
• tungsten oxide
• nanopowders