Nano-scaled Amorphous Iron Oxide of Bacterial Origin ? Its Unique Characters and Extraordinary Functions

Takada, Jun

/ Project leader
/ Graduate School of Natural Science and Technology,
/ Professor / jtakada[at]

Iron-oxidizing bacteria" produce extracellular, uniquely-shaped microsheaths or fibrous bundles mainly composed of iron oxides [named "Biogenous iron oxides (BIOX)"] ubiquitously in natural hydrosphere at ambient temperature. Our microscopic and spectroscopic studies proved that BIOX was an ingenious hybrid of organic and inorganic materials produced through the interaction of bacterial exopolymers with aqueous-phase inorganics. Intriguingly, BIOX has a variety of the industrial functions: lithium-ion battery anode material, catalyst enhancer, and porcelain pigment. All these potentials are far beyond those of artificially synthesized iron oxides. We place our hopes and expectations on the eco-friendly, nontoxic, low-cost BIOX as a fascinating functional material for the next generation.

Reference: H. HASHIMOTO, G. KOBAYASHI, R. SAKUMA, T. FUJII, N. HAYASHI, T. SUZUKI, R. KANNO, M. TAKANO and J. TAKADA, “Bacterial Nanometric Amorphous Fe-Based Oxide; A Potential Lithium-Ion Battery Anode Material”, ACS Appl. Mater. Interfaces, vol.6,no.8, pp.5374–5378 (2014)


Photograph and micrographs of L-BIOX. (a) Ocher L-BIOX in a stream. (b) Low and (c) high-magnification SEM images of L-BIOX.