Z-scheme TiO2-Au@CN heterojunction for simultaneous water purification of disinfection and organic pollutant removal by simulated solar light

Abstract

Simultaneous water purification of multiple hazardous pollutants assisted by photocatalysis technology is regarded as an environmentally friendly and energy-smart strategy under the background of energy and water crisis. Herein, a Z-scheme heterojunction of TiO2-Au@CN nanofibers was constructed. The CB and VB with high potentials were maintained due to the merit of Z-scheme heterojunction. By simultaneous excitement of TiO2 and CN, the TiO2-Au@CN composites presented excellent photocatalytic performance for coinstantaneous 86% inactivation rate against E.coli and 93% RhB removal within 60 min under simulated solar light irradiation. The promoted photocatalytic performance probably resulted from Z-scheme electron transfer mechanism at the interface of the heterojunction assisted by AuNPs as an electron mediator. Moreover, the photocatalytic degradation and disinfection process mainly occurred at surface active sites separately on CB from CN and VB from TiO2, respectively. The constructed Z-scheme heterojunction with efficient light utilization showed great potential in practical water purification under sunlight.