Cr-hollandite: Breaking tradition with todorokite-type manganese oxides

Synthesis of a new hollandite-type manganese oxide with framework and interstitial Cr(III).

Hollandite with Cr(III) in both tunnel and framework sites has been prepared hydrothermally from layered manganese oxide precursors.

Crystalline todorokite associated with biogenic debris in manganese nodules.

Platy intergrowths of crystalline todorokite are associated with biogenic debris in the cores of manganese nodules from a site in the Pacific Ocean. Analyses by electron diffraction and transmission electron microscopy demonstrate that this material is composed of tunnels of chains of linked MnO(6) octahedra. The chemical composition, morphology, and stability of the todorokite differ from thos...

Nanocrystalline todorokite-like manganese oxide produced by bacterial catalysis.

We describe the characterization of an unknown and difficult to identify but geochemically and environmentally significant MnOx structure produced by a freshwater bacterium, Leptothrix discophora SP-6, using combined transmission electron microscopy (TEM), extended X-ray absorption fine structure (EXAFS), and UV Raman spectroscopy. The large surface-to-volume ratio of the needle-shaped nanocrys...

Todorokite-type manganese oxide nanowires as an intercalation cathode for Li-ion and Na-ion batteries

An Electrochemical Sensor Based on Nanostructured Hollandite-type Manganese Oxide for Detection of Potassium Ions

The participation of cations in redox reactions of manganese oxides provides an opportunity for development of chemical sensors for non-electroactive ions. A sensor based on a nanostructured hollandite-type manganese oxide was investigated for voltammetric detection of potassium ions. The detection is based on the measurement of anodic current generated by oxidation of Mn(III) to Mn(IV) at the ...