摘要
How to utilize inexhaustible solar light as a means of disinfection technology for its cheap and green remains a challenge.In this work,core-shell ZnO@ZIF-8 was synthesized and used for bacterial inactivation synergizing with peroxymonosulfate(PMS)under visible light irradiation.It took 50 min to achieve thorough sterilization for 7.5-log Escherichia coli(E.coli)cells in vis/PMS/ZnO@ZIF-8 system,compared with that 4.5-log reduction completed in vis/PMS/ZnO system under the same conditions.The enhanced photocatalytic disinfection mechanisms of fabricated ZnO@ZIF-8 were investigated by UV-vis diffuse reflectance spectra,electrochemical impedance spectra and Mott-Schottky plots.The promoted bactericidal efficiency was attributed to higher charge-separation efficiency and stronger oxidation ability of photo-generated holes.Moreover,it was found that^(1)O_(2)and·OH induced bacterial cell lesion process,and the former was the main active species.The external reactive oxygen species(ROS)caused a series of cell wall damage,intercellular ROS up-regulation and genome DNA unwinding,finally resulted in irreversible bacterial death.A two-route mechanism in vis/PMS/ZnO@ZIF-8 system was proposed,in which the generation of^(1)O_(2)was supposed as the product of the oxygen oxidation of photo-generated holes and PMS dissociation.Our work is expected to provide advanced information about a low-cost water disinfection technology of visible light photocatalysis.
基金
the financial support from National Natural Science Foundation of China(No.52070133)
Sichuan Science and Technology Program:Key Research and Development Program(Nos.2019YFG0314,2017SZ0180,2019YFG0324)。
