Cost-effective, self-powered all-around disinfection system based on double-ring triboelectric nanogenerator

The transmission of infectious diseases by bacteria in air and drinking water represents a significant challenge to public health. However, the majority of existing disinfection methods are dependent on a power grid and cannot achieve simultaneous disinfection when both air and drinking water are contaminated. Here a cost-effective, self-powered all-around disinfection system was developed based on double-ring triboelectric nanogenerator (DR-TENG) with an outer-ring TENG (OR-TENG) and an inner-ring TENG (IR-TENG). The double-ring structure enables DR-TENG to achieve an average power of up to 188.74 mW, which is approximately 1.20 and 2.05 times higher than that of traditional TENGs with OR-TENG and IR-TENG structures only, respectively. Subsequently, the two outputs of OR-TENG and IR-TENG can power UV lamps and tubular coaxial-electrode copper ionization cell (CECIC), respectively, for the simultaneous disinfection of air (>5-log disinfection efficiency within 5 min) and drinking water (>6-log disinfection efficiency at the HRT of 2 min), which breaks the limitation that traditional TENG-driven disinfection systems can only achieve disinfection in a single environment (air or water). A systematic investigation was conducted to examine the phenomenon of a reduction in disinfection efficiency with an increase in electric conductivity during CECIC drinking water disinfection. Meanwhile, the self-powered system is independent of the power grid, and a cost as low as $12.92 for a 2-year service enables the system to be cost-effective and expands the application scenarios. In the practical environment, the self-powered disinfection system can be used for simultaneous disinfection of air and drinking water in remote energy-scarce areas or densely populated spaces such as hospitals and schools, and will potentially promote family medical care and public health.