Chemical tuning polymorphology of functional materials by hydrothermal and solvothermal reactions

Both hydrothermal and solvothermal reactions have been employed to chemically tune the polymorphology of functional materials, such as ZnO, ZnS, BaCO3, magnesium salts, copper salts, and lithium niobate. Novel self-assembled nest-like Mg5(CO3)4(OH)2 4H2O microspheres are formed without any organic additive or catalyst. Malachite [Cu2(OH)2CO3] with a hierarchical sphere-like architecture and lindgrenite [Cu3(OH)2 (MoO4)2] with a hollow and pricky sphere-like architecture have been synthesized via a simple and mild hydrothermal route. Uniform hexagonal pencil-like BaCO3 whiskers have been synthesized by the chemical reaction of barium chloride and urea via a facile hydrothermal route. The solvothermal route has also been successfully demonstrated to the synthesis of cube-shaped lithium niobate and complex ZnO. Our results demonstrate that hydrothermal or solvothermal reactions can be used as a versatile route to the chemical synthesis of tuning polymorphology of functional materials.