Silver molybdate
Silver molybdate is an inorganic compound with the chemical formula Ag2MoO4. It is a yellow solid that crystallizes in the cubic system and exhibits dimorphism. It is often used in glass.
Structure
Silver molybdate crystals present two types of electronic structure, depending on the pressure conditions to which the crystal is subjected. At room temperature, it exhibits a spinel-type cubic structure, known as β-Ag2MoO4, which is more stable in nature. However, when exposed to high hydrostatic pressure, the tetragonal α-Ag2MoO4 forms as a metastable phase.Synthesis and properties
α-Ag2MoO4
α-Ag2MoO4 can be prepared by solution-phase precipitation under ambient conditions, using 3-bispyrazine as a doping agent. The pH of the starting solution influences the growth and formation processes of distinct heterostructures.β-Ag2MoO4
β-Ag2MoO4 crystals can be prepared by solid-state reaction or oxide mixture at high temperature, melt-quenching, and Czochralski growth.Additional methods include co-precipitation, microwave-assisted hydrothermal synthesis, a dynamic template route using polymerization of acrylamide assisted templates, and an impregnation/calcination method.
β-Ag2MoO4 microcrystals can be synthesized by precipitation employing polar solvents.
Photocatalytic properties of β–Ag2MoO4 crystals can be improved through hydrothermal processing at different temperatures. The replacement of Ag atoms with Zn to form silver-zinc molybdate microcrystals by a sonochemical method also leads to improvements. These crystals are able to degrade rhodamine B and Remazol Brilliant Violet 5R.