Synthesis of adjustable {312}/{004} facet heterojunction MWCNTs/Bi5O7I photocatalyst for ofloxacin degradation: Novel insights into the charge carriers transport

Multi-wall carbon nanotubes (MWCNTs) with high electrical conductivity are commonly accounted as the ideal additives to enhance the charge surface migration efficiency in photocatalysis. Theoretically, the MWCNTs-modified binary photocatalysts have potential for the change of nanocrystal structure. Herein, we reports an adjustable {312}/{004}facet heterojunction MWCNTs/Bi5O7I nanocomposite. Interestingly, the synergistic effect of {312}/{004}facet heterojunction and MWCNTs can effectively accelerate the spatial charge carriers transport. A novel {312}/{004}facet “S-scheme” pathway was proven to be the dominated pathway for the enhancement of spatial charge carriers. As a result, the MWCNTs-{312}/{004}Bi5O7I composites exhibited superior photocatalytic oxidation efficiency for a representative antibiotics ofloxacin photodegradation. Density functional theory (DFT) calculation and LC-MS/MS analysis confirmed that the possible dealkylation and oxidation pathways could be found in OFL degradation. This work provides novel insights for the relationship between charge carrier transport and facet structure-property. [Display omitted] •MWCNTs induce the {312}/{004} facet ratio change of Bi5O7I photocatalysts.•Facet heterojunction is a major transport pathway of charge carrier.•The h+ and •O2- radicals are dominant reactive species in the photocatalysis.•Acetic acid is firstly found in the ofloxacin photodegradation.