Photocatalytic properties of β-pyrochlore RbTe1.5W0.5O6 under visible-light irradiation

Previous electron structure investigation of β-pyrochlore type compound with composition RbTe1·5W0·5O6 shows that it can photocatalyze oxidation process of organic pollutants under visible light irradiation. In this paper, β-pyrochlore of composition RbTe1·5W0·5O6 has been studied as photocatalysts for decomposition of organic dyes. The powder was prepared by solid-state reaction; particles size has been changed by grinding in planar mill and characterized by laser diffraction and static volumetric methods. The dependence on the photocatalytic properties of particles size, dye type and mass has been studied. The sample on all stages of process has been characterized by X-ray diffraction analysis, and scanning electron microscopy with X-ray microanalysis. Composition and valence states of elements on the RbTe1·5W0·5O6 surface have been investigated by X-ray photoelectron spectroscopy on all stages of photocatalytic experiment, and the obtained results show high role of Rb atoms in the photooxidation process. [Display omitted] •Photocatalytic oxidation process of methylene blue under visible light irradiation using RbTe1·5W0·5O6 has been studied.•Adsorption kinetic model has been determined.•The dependence of photooxidation on dye type has been obtained.•The significant role of Rb atoms in photocatalysis process has been confirmed by X-ray photoelectron spectroscopy.•The surface composition during photocatalysis has been investigated using X-ray photoelectron spectroscopy.