Fabrication of hexagonal/cubic tungsten oxide homojunction with improved photocatalytic activity

Abstract

A homojunction with different phases of tungsten oxide photocatalyst was prepared via a hydrothermal method by adjusting the pH value. The structural analysis showed the homojunction consisted of tungsten bronze-type (hexagonal) and pyrochlore-type (cubic) structures. The rod-like hexagonal phase inserted into block cubic phase to form a well-defined homojunction structure under the proper pH condition. The activity of photocatalyst was tested through degradating RhB and water oxidation. The results indicated the homojunction photocatalyst displayed a higher photocatalytic activity compared with individual tungsten oxide under visible light and full sunlight spectra irradiation. The further investigations revealed the inner electric filed at the interface of the homojunction facilitated the separation of electron-hole pairs, resulting in the improved photoelectrochemical performance. The design of favorable tungsten oxide homojunction structure in the present work provided a promising method for the development of other efficient photocatalysts.