The hydrothermal method is a technique used to synthesize materials, particularly in the field of chemistry and materials science. This process involves using high-temperature and high-pressure water to facilitate chemical reactions. It is commonly employed to produce crystals, nanoparticles, and other materials that require specific conditions for growth. In this method, a solution containing the desired reactants is placed in a sealed vessel, often called an autoclave. The vessel is then heated, allowing the water to reach supercritical conditions, which enhances solubility and reaction rates. This technique is widely used for creating materials like zeolites, metal oxides, and nanomaterials.