Simultaneous precipitation and discharge plasma processing for one-step synthesis of α-Fe 2 O 3 -Fe 3 O 4 /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 α-Fe 2 O 3 -Fe 3 O 4 graphene nanocomposite (GFs). The co-existence and anchoring of hematite (α-Fe 2 O 3 ) and magnetite (Fe 3 O 4 ) 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 α-Fe 2 O 3 /Fe 3 O 4 nanoparticles and the graphene sheet. Consequently, GFs shows superior photodegrading performance towards methylene blue (MB), compared to individual α-Fe 2 O 3 /Fe 3 O 4 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.