Nondimensional Reaction-Diffusion Model of Plasma-Liquid Interactions

Plasma-liquid interactions create highly reactive environments to enable valuable and diverse chemical transformations. Unlike conventional electrolysis, unique oxidizing and reducing species are generated, and unlike conventional radiolysis, reactions are driven without using powerful radiation (e.g. high-energy electron, gamma) sources. However, selectivity remains challenging because of complex coupling of interfacial transport and kinetics involving the injected radicals and dissolved substrates. Here, we present a unified nondimensional model based on classical film theory to analyze reaction-diffusion in plasma-liquid systems. The model reveals distinct regimes such as mass transport-limited and kinetically-limited cases. With experimental validation, we demonstrate the utility of the model to extract important operational parameters and guide more rational design of reactors to optimize selectivity.