Cuboid-like Bi2Fe4O9/Ag with Graphene-Wrapping Tribrid Composite with Superior Capability for Environmental Decontamination: Nanoscaled Material Design and Visible-Light-Driven Multifunctional Catalyst

摘要

A cuboid-like Bi2Fe4O9/Ag with graphene-wrapping tribrid nanoarchitecture was fabricated using a delicate multistep synthesis process. It is designed to effectively enhance the performance of the pristine Bi2Fe4O9 in the removal of organic pollutants [up to 97% of methylene blue (MB) removal in 30 min under visible light irradiation] through ternary collaboration among Bi2Fe4O9, silver nano-particles (AgNPs), and reduced graphene oxide (rGO). The challenges, such as mass transfer of pollutants in water treatment, recombination of electrons/holes, and interconver-sion between Fe(III) and Fe(II) states within Bi2Fe4O9, could be addressed effectively. The resulting samples (i.e., Bi2Fe4O9/ Ag/rGO, Bi2Fe4O9/Ag, and Bi2Fe4O9) were characterized by various techniques, and their differences in physical and chemical properties were investigated. Meanwhile, their applications in the removal of organic pollutants were assessed via photo-Fenton oxidation and photocatalysis under visible light irradiation. The findings demonstrate the individual functions of AgNP [i.e., electrical conduction and enhanced interconversion of Fe(III) and Fe(II)] and rGO (i.e., antirecombination of electrons/holes and enhanced mass transfer of organic pollutants) within the Bi2Fe4O9/Ag/rGO composite. A schematic illustration of the mechanism of the removal of organic pollutants using the multifunctional Bi2Fe4O9/Ag/rGO is presented.