Synthesis and Properties of (Ca/Sr)1 – 3xBi2xMoO4 Solid Solutions

Abstract

We have synthesized CaMoO₄- and SrMoO₄-based scheelite-like compounds and located the stability ranges of (Ca/Sr)_{1 – 3x}Bi_2xMoO₄ solid solutions (x = 0.2125). The materials with x ≥ 0.175 have been shown to undergo superstructure ordering related to the arrangement of cation vacancies in their structure. The reflection spectra of the solid solutions have been measured and their band gap for direct transitions has been shown to range from 2.8 to 3.5 eV. We have studied photocatalytic properties of the solid solutions using powder samples. The photocatalytic characteristics of Ca_{1 – 3x}Bi_2xMoO₄ under UV illumination have been shown to be comparable to those of titania. The electrical conductivity of Ca_{1 – 3x}Bi_2xMoO₄ is lower than that of Sr_{1 – 3x}Bi_2xMoO₄.