Synthesis of Functional Materials by In-Liquid Plasma Processing

A non-equilibrium plasma, characterized by a significant disparity between electron temperature and ion temperature, offers an enticing environment for various reactions. This unique setting holds the potential to facilitate low-temperature processes in material synthesis and other applications. Particularly noteworthy is the generation of plasma in liquid, which enables reactions to occur at temperatures below the liquid's boiling point, creating a distinctive and promising reaction milieu. We set-up two different cold plasmas: one is a so-called solution plasma using a bipolar pulse power supply. The other is a liquid plasma formed in a high energy state by a microwave power supply. By controlling the power supply conditions for the generation of the in-liquid plasma, the composition of the liquid, and the gas species introduced into the reaction field, we are working to develop materials and processes, aiming to contribute to a sustainable, recycling-oriented society. In the present study, we will introduce the photocatalyst of TiO2 with oxygen-vacancy induced by solution plasma, as well as the diamond synthesis using of in-liquid microwave plasma CVD method.