ZnO coupled F-doped g-C3N4: Z-scheme heterojunction for visible-light driven photocatalytic degradation reaction

Abstract

In this present work, ZnO coupled Fluorine doped g-C3N4 heterojunction has been successfully synthesised by simple wet-chemical method. The structural, optical, morphological, vibrational and charge separation behaviour of the prepared photocatalysts was examined by various characterization techniques. The Fluorine dopant enhances the bandgap of g-C3N4 to 2.84 eV from 2.79 eV. The heterojunction formation between the nanoparticles helps to utilize the more amount of visible-light with low charge recombination rate. The nanocomposite F@g-C3N4/ZnO photocatalyst exhibits Z-scheme mechanism with rhodamine B (Rh B) dye degradation efficiency of 97% and 98% under UV–Vis light and direct sunlight respectively. The elemental trapping experiment reveals superoxide radicals and holes are the main active species for Z-scheme dye degradation process. Moreover, the recycle test confirms the stability nature of the prepared F@g-C3N4/ZnO nanocomposite with 87% degradation efficiency at 5th cycle.