The Photocatalytic Oxidation Ability of Rb0.9Nb1.625Mo0.375O5.62 with Classic β‐Pyrochlore Structure

Abstract Previously the non‐cubic β‐pyrochlore polycrystalline compounds Rb 0.95 Nb x Mo 2‐x O 6.475‐0.5x (x=1.31–1.663) have been obtained in the ternary system Rb 2 O‐Nb 2 O 5 ‐2MoO 3 . However, using special synthesis condition leads to the formation of cubic Fd‐3m β‐pyrochlore Rb 0.9 Nb 1.625 Mo 0.375 O 5.62 with small size particles and surface area of 15 m 2 /g. The Rb 0.9 Nb 1.625 Mo 0.375 O 5.62 powder has been investigated by X‐ray powder diffraction analysis and scanning electron microscopy with X‐ray microanalysis. The crystal structure refinement has been performed using the Rietveld method. The electronic structure and optical band gap of Rb 0.9 Nb 1.625 Mo 0.375 O 5.62 have been studied in comparison to similar non‐cubic composition Rb 0.95 Nb 1.625 Mo 0.375 O 5.66 . The photocatalytic properties of Rb 0.9 Nb 1.625 Mo 0.375 O 5.62 have been investigated on the example for dyes solution oxidation under UV irradiation. The dependence on the photocatalytic properties of dye type and catalyst mass has been studied. It has been observed that the main oxidative species for dye oxidation is hydroxyl radicals. The phase and composition stability of catalyst powder have been confirmed.