Low frequency hydromechanics-driven generation of superoxide radicals via optimized piezotronic effect for water disinfection

Abstract

Water transmission of pathogenic microorganisms can lead to infectious diseases and potential pandemics. Piezocatalysis is an emerging technology for water disinfection, however, current piezocatalysts often have low catalytic performance due to limited charge utilization and require the use of high-frequency ultrasound. Herein, low-frequency hydromechanics is employed as mechanical energy resource to achieve efficient disinfection via a rationally-designed piezocatalyst, BaTiO 3 @Au. The interfacial position of Au cocatalyst was optimized by in situ piezodeposition instead of random chemical reduction, which facilitated charge separation and promoted the generation of reactive oxygen species (ROS). By simply vibrating (e.g., stirring) the piezocatalysts dispersed in aqueous solution, efficient degradation of organic molecules as well as inactivation of model bacteria and virus could be obtained. This approach allowed us to take advantage of low-frequency hydromechanical energy to significantly reduce intestinal pathogenic bacteria and total organic carbon content in hospital wastewater, which could provide a green and feasible way for water disinfection. • Efficient water disinfection was achieved by simply stirring a rationally-designed piezocatalyst. • The hydromechanics-driven piezocatalysis was enabled by optimized piezotronic effect. • A simple in situ piezodeposition of gold on piezocatalysts was introduced. • This strategy was successfully applied for the treatment of wastewater from a local hospital.