Hydrothermal/solvothermal processing of advanced ceramic materials

Ceramic materials/nanomaterials have received considerable interests and attention in materials science due to their potential applications such as to electronics, optics, catalysis, and magnetic storage. From the viewpoint of applications, it is very important to process ceramic materials with well-defined shapes, sizes, and form. However, most ceramic materials processing methods such as solid state reactions, CVD, MOCVD, and PVD involved using higher temperatures, or toxic organometallic precursors, or complicated reaction and post-treatment systems. Exploration of novel, convenient, lower temperature, and environmentally friendly solution processing routes for synthesis of advanced ceramic materials with desired shapes and sizes has been challenged in materials science. This review focuses on the latest development of hydrothermal process, its integration with other activation methods such as electrochemistry, microwave, and its counterpart solvothermal process for fabrication of ceramic thin films, nanoparticles, and single crystals. Especially, as a new emerging process and one complement for conventional hydrothermal process, solvothermal process has proved to play a significant role in synthesis of advanced non-oxide ceramic materials by using reactions in non-aqueous solutions, which will be an exciting and promising field fur preparation of ceramic materials. Shapes, sizes, and phases of the synthesized ceramics are expected to be well controlled by employing different solution processes, which will play a key role in tailoring the properties of ceramic materials. These new innovations in hydrothermal/solvothermal processing may find wide applications in rational design of advanced ceramic materials in future.