Abstract
<title>Abstract</title> <p>Within the traditional framework of free radical (FR) kinetics, external physical fields (e.g., light, electricity) are generally regarded merely as excitation sources for reactions. Once FR are produced, their subsequent evolution is considered to be governed only by thermodynamic fluctuations and diffusion kinetics, and the non-equilibrium variability that continuous physical field interference may confer on transient FR has long been overlooked. This study presents an interfacial light-focusing strategy that increases the penetration limit of 185 nm VUV light in water by more than two times. By constructing radical cluster structures at 3–20 nm scales using field-dependent density functional theory, the evolution process of electronic spin states and the steady-state boundaries of radical clusters under a continuous light field were clarified. The Independent Gradient Model based on Hirshfeld partition (IGMH) shows that this perturbation causes symmetry breaking, resulting in a clear shift of the reaction potential well toward target pollutant degradation. This dynamic variation explains the leap-frog improvement in activation efficiency observed by quantitative detection. The present study shows that external physical fields are not only initiation sources for FR, but may also actively control the dynamic activation energy of FR systems. The superior performance obtained in Total Organic Carbon (TOC) removal for electronic-grade ultrapure water production and deep mineralization of per- and polyfluoroalkyl substances (PFAS) under complex water backgrounds further confirms the practical value of this mechanism.</p>