Kazuo Terashima

Plasma, owing to its reactivity and nonequilibrium properties, is a unique field commonly used in material processing. In recent years, plasma processing with a liquid phase has attracted considerable attention owing to its important advantages, such as high electron density and the availability of a wide variety of reactions in solutions. However, plasma‐in‐liquid material synthesis is occasionally difficult to control and guidelines are lacking. In this study, we investigated whether the hard‐soft acid–base (HSAB) principle, which is often applied in material synthesis, is applicable to the plasma‐in‐liquid process and demonstrated that organic solvent‐derived substances produced by plasma‐in‐liquid processing reacted with solutes according to the HSAB principle. These results suggest that the HSAB principle may apply to plasma‐in‐liquid processing.