Silicaphosphate Nanomaterials and Nanocomposites Doped with ZrO2 and TiO2: Structure, Functional Properties and Practical Application. Review

Functional properties of silicaphosphates and their application field strongly depend on their chemical composition, especially on dopants. Among dopants, zirconium and titanium oxides occupy special position due to their ability to form insoluble phosphates enhancing linkage of silicaphosphate fragments, and also due to low toxicity. ZrO2 and TiO2 are available, since they can be obtained directly from the solutions, which are formed during the treatment of mineral feedstock. Silicaphospahes doped with ZrO2 and TiO2 can be divided to the materials, which include nanoparticles (nanocomposites possessing sorption properties) or nanosized pores (glasses for biomedical application and energy needs). In this chapter, silicaphosphate scaffolds are considered, protonic and Li-conductors are in a focus of attention, sorbents are also reviewed. Functional properties of obtained materials are described. It is noted that a key way, which allows one to produce silicaphosphate nanomaterials, is sol–gel method. However, for the large-scale production of silicaphosphates like ZrO2–SiO2–P2O5, technological solutions can be used. These solutions, which contain both Zr and Si, are formed during the treatment of zircon, particularly under autoclave conditions.