Solvothermal synthesis

Solvothermal synthesis has been used prepare MOFs, titanium dioxide, and graphene, carbon spheres, chalcogenides and other materials.

Solvents

Besides water (hydrothermal synthesis), solvothermal syntheses make use of a large range of solvents, including ammonia, carbon dioxide, dimethylformamide, and various alcohols such as methanol, or glycols such as hexane-1,6-diol.

Formic acid as reaction medium

Formic acid decomposes at high temperatures to carbon dioxide and hydrogen or carbon monoxide and water. This property allows formic acid to be used as a reducing and carbon dioxide-rich reaction medium in which it is possible to form various oxides and carbonates.

Ammonia as reaction medium

The critical temperature and pressure of ammonia are 132.2 °C and 111 bar. In these conditions, it is possible to obtain a range of amides, imides, and nitrides. Although its dielectric constant is lower than that of water, ammonia behaves as a polar solvent especially at high pressures.