Dual couples Bi metal depositing and Ag@AgI islanding on BiOI 3D architectures for synergistic bactericidal mechanism of E. coli under visible light

Abstract

Ag@AgI/Bi-BiOI (AABB) three-dimentional (3D) nanoarchitectures, synthesized by solvothermal reaction and photoreduction method, were used as high–effective visible light driven (VLD) photocatalysts for the inactivation of Escherichia coli K–12 (E. coli K–12) and were characterized by TEM, SEM, XRD, BET, XPS and DRS. The prepared 30%AABB exhibited the best bacteria disinfection efficiency, and the quantity of viable bacteria could almost inactivate after being illuminated for 18min. The enhanced photocatalytic performance can be attributed to the improved separation efficiency of the photogenerated electron–hole pairs because of its multivariant nanoarchitectures with simultaneous electron transfers (Bi→BiOICBM→Ag→AgIVBM). Furthermore, the SEM technology was applied to certify the photocatalytically lethal effect to E. coli K–12 and the rupture of bacterial membranes. In this work, the antibacterial mechanism was studied by employing Photoluminescence (PL), Photoelectrochemical Techniques, Electron Spin Resonance (ESR), and scavengers of different reactive species, revealing the pivotal roles of h+, e−, and O2− in the photocatalytic process. This study indicated that the fabricated AABB photocatalysts could be potentially utilized to disinfect bacteria in water.