title: Iron Oxide Nanowires from Bacteria Biofilm as an Efficient Visible-Light Magnetic Photocatalyst.
abstract: Naturally produced iron oxide nanowires by Mariprofundus ferrooxydans bacteria as biofilm are evaluated for their structural, chemical, and photocatalytic performance under visible-light irradiation. The crystal phase structure of this unique natural material presents a 1-dimensional (1D) nanowire-like geometry, which is transformed from amorphous to crystalline (hematite) by thermal annealing at high temperature without changing their morphology. This study systematically assesses the effect of different annealing temperatures on the photocatalytic activity of iron oxide nanowires produced by Mariprofundus ferrooxydans bacteria. The nanowires processed at 800 °C were the most optimal for photocatalytic applications degrading a model dye (rhodamine B) in less than an hour. These nanowires displayed excellent reusability with no significant loss of activity even after 6 cycles. Kinetic studies by using hydrogen peroxide (radical generator) and isopropyl alcohol (radical scavenger) suggest that OH• is the dominant photooxidant. These nanowires are naturally produced, inexpensive, highly active, stable, and magnetic and have the potential to be used for broad applications including environmental remediation, water disinfection, and industrial catalysis.
authors.forename: Luoshan
authors.initials: L
authors.lastname: Wang
authors.forename: Tushar
authors.initials: T
authors.lastname: Kumeria
authors.forename: Abel
authors.initials: A
authors.lastname: Santos
authors.affiliation: South Australian (SA) Water , Adelaide, SA 5005, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Forward
authors.forename: Martin F
authors.initials: MF
authors.lastname: Lambert
authors.forename: Dusan
authors.initials: D
authors.lastname: Losic
mesh_terms: D001419:Bacteria; D018441:Biofilms; D002384:Catalysis; D005290:Ferric Compounds; D007700:Kinetics; D008027:Light; D053770:Nanowires
chemical_list: D005290:Ferric Compounds; C000499:ferric oxide
keywords: bacteria biofilm; iron oxide nanowires; natural nanostructure; rhodamine B; visible-light photocatalysis