Hydrothermal Synthesis of Molybdenum Oxide Based Materials: Strategy and Structural Chemistry

Abstract

The preparative flexibility of hydrothermal syntheses needs to be systemised for exploring complex structure-synthesis relationships and morphology control options in materials chemistry. This is demonstrated for the targeted hydrothermal preparation of molybdenum oxide materials: firstly, in situ studies were employed for the efficient production of MoO(3) nanofibres. Furthermore, ionic substances as structure-directing tools brought forward a new class of fluorinated polyoxomolybdates.

Renewable chitin from marine sponge as a thermostable biological template for hydrothermal synthesis of hematite nanospheres using principles of extreme biomimetics

“…A broad variety of reactions related to hydrothermal synthesis can be performed in vitro. This feature is also promising for chitin surface metallization, which normally requires temperatures up to 300 °C [29] and pH between 1 and 14 [30]. It is important to note that Extreme Biomimetics based on a combination of hydrothermal synthesis and utilization of morphologically defined 3D chitin structures perfectly aligns with green chemistry concepts [31][32][33][34].…”

A New Class of Nanostructured Inorganic–Organic Hybrid Semiconductors Based on II–VI Binary Compounds

“…Solvothermal (hydrothermal) synthesis (126)(127)(128)(129)(130)(131)(132)(133) involves use of a solvent (water) at elevated temperatures and pressures in a closed system, often in the vicinity of its critical point. Under solvo(hydro)thermal conditions, certain properties of the solvent (e.g., density, polarity, viscosity, and diffusion coefficient), change dramatically, and the solvent acts very differently from its normal behavior under ambient conditions (133,134).…”

“…This result allows the reaction to take place at much milder conditions (e.g., lower temperatures, <250 C). The method has emerged in recent years as one of the most powerful crystal growth techniques and received tremendous interests in synthetic chemistry and materials science (131)(132)(133)(135)(136)(137)(138)(139)(140)(141). A great number of solid-state compounds [e.g., metal chalcogenides (130,(141)(142)(143)(144), phosphides (145)(146)(147)(148)(149)(150)(151)(152)(153), metal nitrides (141,(154)(155)(156)(157), and interesting metastable phases (157)(158)(159)(160)(161)(162)(163)(164)], have been produced by employing this technique.…”

New structural units in molybdenum oxyfluoride chemistry

“…We note that the majority of these examples are purely inorganic, though there are a couple of 'hybrid' cases. In addition, there are further examples of 'fluorinated polyoxomolybdates', which have typically higher O/F ratios 21,22 . We have now begun to explore the solvothermal chemistry of molybdenum in fluorine-rich environments, and here we report some of our preliminary results, in which we isolate three novel structural/compositional building units, each containing Mo in a partially reduced oxidation state.…”