Sheelite-related strontium molybdates: synthesis and characterization

Abstract

Sheelite-related strontium molybdates: synthesis and characterizationThe present research is devoted to the cationic-deficient SrMoO 4 -based sheelite-related complex oxides. The doping with bismuth to A sublattice and codoping with bismuth and vanadium (to A and B sublattices, respectively) were discussed. The X-Ray powder diffraction and infrared spectroscopy were used to investigate structural characteristics of the complex oxides. In Sr 1-1.5x Bi x MoO 4 , a superstructural ordering was observed. Conductivity and dielectric loss of ceramic samples are measured using alternating current.

ABO4 type scheelite phases in (Ca/Sr)MoO4 - BiVO4 - Bi2Mo3O12 systems: synthesis, structure and optical properties

“…But for oxides with higher x values the additional peaks in the XRD patterns are evident. These oxides were found to have the tetragonal supercell with a sup ≈ √5a, c sup ≈ c, where a and c are the tetragonal scheelite cell parameters, like it was found earlier for Ca 1−3x Bi 2x Mo 1 O 4[19] and Sr 1−3x Bi 2x Mo 1 O 4[20]. The areas of solid solutions (ordinary scheelite and superstructured scheelite) and inveatigated fields of triple phase diagram are shown at Fig.1.…”

“…Bi x Mo 1-x V x O 4 oxide is observed[20]. In general, Bi-and (Bi+V) doped CaMoO 4 and SrMoO 4 show the decreasing melting point temperature and, as a consequence, lower sintering temperature, as well as increasing conductivity, catalytic and photocatalytic activity.…”

“…Samples described with supercell showed maximal photocatalytic activity due to complex microstructure at grain surface and also showed a decrease of total conductivity as compared to samples with normal scheelite structure [19]. [20]. In contrast, Ca 1-x Bi x Mo 1-x V x O 4 single-phase solid solutions are observed for 0 ≤ x ≤ 0.9 [6].…”

Improved the methanol electrooxidation and carbon monoxide tolerance for direct methanol fuel cells using strontium molybdate

“…In the present study, 20% Pt loading on strontium molybdate mixed with carbon black was prepared as the electrocatalyst to successfully improve MOR and CO tolerance in fabricated DMFCs. Strontium molybdate is a scheelite-type complex oxide [27] that consists of Sr 2+ cations and (MoO 4 ) 2− anions. It has been used recently in electrocatalysts to increase hydrogen evolution reaction activity in acid water electrolytes [28] when applied to the electrochemical determination and photocatalytic degradation of diphenylamine [29] and tetracycline [30].…”

“…XRD results of uncalcined MoO 3 were analyzed in our previous study [58] and indicated MoO x or molybdenum trioxide hydrate (MoO 3 •H 2 O) compounds. Therefore, whenSr was mixed with Mo precursors to prepare SrMoO 4 , the substitutional incorporation of Sr 2+ ions at Mo 6+ sites depends on the ionic radius of Sr 2+ (1.26 Å), which is larger than that of Mo 6+ (0.41 Å)[27]. This leads to immediate formation of SrMoO 4 crystal structure without calcination.…”