Tunable Biogenic Manganese Oxides

Alexandr N. Simonov, Rosalie K. Hocking, Lizhi Tao, Thomas R Gengenbach, Timothy Williams, Xi Ya Fang, Hannah J King, Shannon A. Bonke, Dijon A. Hoogeveen, Christine A. Romano, Bradley M. Tebo, Lisandra L. Martin, William H. Casey, Leone Spiccia

Research output: Contribution to journalArticleResearchpeer-review

7 Citations (Scopus)


Influence of the conditions for aerobic oxidation of Mn2+(aq) catalysed by the MnxEFG protein complex on the morphology, structure and reactivity of the resulting biogenic manganese oxides (MnOx) is explored. Physical characterisation of MnOx includes scanning and transmission electron microscopy, and X-ray photoelectron and K-edge Mn, Fe X-ray absorption spectroscopy. This characterisation reveals that the MnOx materials share the structural features of birnessite, yet differ in the degree of structural disorder. Importantly, these biogenic products exhibit strikingly different morphologies that can be easily controlled. Changing the substrate-to-protein ratio produces MnOx either as nm-thin sheets, or rods with diameters below 20nm, or a combination of the two. Mineralisation in solutions that contain Fe2+(aq) makes solids with significant disorder in the structure, while the presence of Ca2+(aq) facilitates formation of more ordered materials. The (photo)oxidation and (photo)electrocatalytic capacity of the MnOx minerals is examined and correlated with their structural properties.

Original languageEnglish
Pages (from-to)13482-13492
Number of pages11
JournalChemistry - A European Journal
Issue number54
Publication statusPublished - 27 Sept 2017


  • Biogenic materials
  • Manganese
  • MnxEFG protein complex
  • Structural disorder
  • Structure elucidation
  • Tunable morphology

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