Simultaneous precipitation and discharge plasma processing for one-step synthesis of alpha-Fe2O3-Fe3O4/graphene visible light magnetically separable photocatalysts

A novel facile combination of precipitation and plasma discharge reaction is successfully employed for one-step synthesis of an alpha-Fe2O3-Fe3O4 graphene nanocomposite (GFs). The co-existence and anchoring of hematite (alpha-Fe2O3) and magnetite (Fe3O4) nanoparticles onto a graphene sheet in the as synthesized GFs were verified by results of XRD, Raman, SEM, TEM, and XPS. HRTEM characterization was used for confirming the bonding between alpha-Fe2O3/Fe3O4 nanoparticles and the graphene sheet. Consequently, GFs shows superior photodegrading performance towards methylene blue (MB), compared to individual alpha-Fe2O3/Fe3O4 nanoparticles, as a result of band gap narrowing and the electron-hole pair recombination rate reducing. Moreover, GFs allows a good possibility of separating and recycling under an external-magnetic field, suggesting potential in visible-light-promoted photocatalytic applications.