Degradation of organic molecules by tribovoltaic mechano-chemistry

The presence and accumulation of organic pollutants in water systems is a significant threat to the health of humans and aquatic ecosystems. Herein we demonstrate a new mechanism for high-efficient degradation of organic molecules based on the tribovoltaic effect. The method does not require photo-irradiation nor external power sources, but only use mechanical energy to generate electron-hole (e-h) pairs at dynamic metal-semiconductor contacts. Under short-circuit condition, e-h pairs in the heterojunction manifest themselves as direct-current (DC) output. Interacting with water under stirring or ultrasonication, the e-h pairs excited by collision between metal and semiconductor particles are capable of generating highly reactive free radicals and driving dye molecule degradation. Such mechano -catalysis mechanism is proved to be a versatile strategy with a broad range of material selection and mechanical stimuli, which has great implications for cost- and energy-effective water treatment, as well as potential applications in green chemical synthesis.