Heterojunction of g-C3N4/BiOI Immobilized on Flexible Electrospun Polyacrylonitrile Nanofibers: Facile Preparation and Enhanced Visible Photocatalytic Activity for Floating Photocatalysis

The heterojunction of g-C3N4/BiOI was uniformly immobilized on electrospun polyacrylonitrile (PAN) nanofibers via a facile in situ synthesis at room temperature. X-ray photoelectron spectra showed that both the C and N 1s peaks of PAN/g-C3N4/BiOI nanofibers shifted to higher binding energies as compared to those of PAN/g-C3N4 nanofibers suggesting electron transfer from g-C3N4 to BiOI during the formation of heterojunctions. The enhanced photocurrent densities and significant decrease in photoluminescence intensity confirmed the effective charge separation at the heterojunction interfaces in PAN/g-C3N4/BiOI nanofibers. The efficient separation of the electron–hole pairs and their strong absorption in the visible region results in superior photocatalytic activities in the degradation of Rhodamine B (RhB) dyes and toxic Cr(VI) ions under visible-light irradiation versus PAN/g-C3N4 and PAN/BiOI nanofibers. Moreover, the filmlike PAN/g-C3N4/BiOI nanofibers have ultralong one-dimensional nanostructures and flexible self-supporting structures that can be used as useful floating photocatalysts. They can float easily on liquid and are directly reused without separation during the photocatalytic reaction. These results demonstrate that flexible PAN/g-C3N4/BiOI nanofibers with high photocatalytic activity and excellent reusability have potential in wastewater treatment.