EXPRESS: Imaging Spectroscopy at the Plasma–Liquid Interface

This contribution presents a novel, simple and cost-effective method for observing the movement of reaction products out of the plasma–liquid interface (PLI). By employing an imaging spectrograph, a multidimensional view, i.e., spatial, spectral, and temporal, of reactions occurring at the PLI is made possible, including the ability to track the reactions from the interface to bulk. Ultraviolet–visible (UV–Vis) absorption spectroscopy techniques are key for interpreting changes in the observed section, and these techniques allow for calculating concentrations, determining production rates, and identifying reaction pathways. We describe and specify a direct vision imaging spectrograph and demonstrate its application to the aforementioned task. This approach provides valuable insight into the dynamics at the PLI and is a promising method for studying reaction kinetics and mechanisms in similar systems. Imaging spectroscopy is a valuable tool for analyzing the spatial, spectral, and temporal dynamics of plasma–liquid interactions. Our findings provide new insights into the complex physical and chemical processes which occur in such systems; they offer a deeper understanding of plasma-induced phenomena at the liquid interface. As a consequence, this research furthers possibilities for optimizing plasma-driven chemical reactions.