Continuous Flow Synthesis of Nanoparticles Using Supercritical Water: Process Design, Surface Control, and Nanohybrid Materials

A continuous flow reaction process in which a metal salt solution is rapidly mixed with high-temperature water was employed to achieve rapid heating up to supercritical conditions. A quarter of a century has passed since the supercritical hydrothermal method was first proposed. This paper introduces recent advances in science and technology related to the supercritical process. Process design, kinetics, reaction atmosphere (redox) control, morphology control, organic modification of particles, nanocatalysts, and organic-inorganic hybrid materials are reviewed for promising applications of the supercritical process.