A triboelectric radical generation route to chlorine disinfectants from brine

Abstract Contact electrification (CE), one of the earliest documented physical phenomena, has traditionally been associated with triboelectric charging but rarely considered as a driver of chemical transformations. Here we show that CE generates radicals at solid-liquid interfaces, establishing contact-electro-chemistry (CE-Chemistry) as a metal-catalyst-free route that uses ambient mechanical energy. Ultrasonically driven contact-separation of fluorinated ethylene propylene (FEP) particulates in brine generates hydroxyl radicals (•OH) and chlorine radicals (•Cl), forming active chlorine [hypochlorous acid (HOCl) and hypochlorite ions (ClO − )], without detectable chlorine gas (Cl 2 ) production. Using natural seawater, this strategy achieves active chlorine production of 208.8 μmol g −1 h −1 and operates for over 700 h without detectable FEP dissolution or toxic intermediates. Cation hydration engineering modulates interfacial electrical double layers, strengthening triboelectric fields and tuning reaction kinetics. This work enables Cl 2 -free disinfectant production from brine without external bias or illumination, opening avenues for heterogeneous catalysis and CE-driven reaction design.