Single-electron-mediated redox processes at the air-water interface of water microdroplets
Water is typically regarded as a stable solvent;however,when dispersed into microdroplets,it exhibits numerous distinctive properties.The most notable one among these properties is the spontaneously formed electric field on the surface of microdroplets,reaching up to 109 V m-1.This electric field has the capacity to dislodge electrons from hydroxide ions or from closed-shell molecules in water,yielding radicals and electrons.Consequently,this process further initiates redox reactions.This article provides a comprehensive overview of more than 40 types of single-electron-mediated spontaneous redox reactions occurring on the surfaces of water microdroplets.The corresponding reaction kinetics is discussed,underscoring the intrinsic electron-driven nature of these reactions.Finally,by integrating perspectives from synthetic chemistry and atmospheric chemistry,we explore and anticipate the broad and potential impacts of the redox capabilities of microdroplets.