Nanoscale Hydration in Layered Manganese Oxides.

ABSTRACT: Birnessite is a layered MnO₂ mineral capable of intercalating nanometric water films in its bulk. With its variable distributions of Mn oxidation states (Mn^IV, Mn^III, and Mn^II), cationic vacancies, and interlayer cationic populations, birnessite plays key roles in catalysis, energy storage solutions, and environmental (geo)chemistry. We here report the molecular controls driving the nanoscale intercalation of water in potassium-exchanged birnessite nanoparticles. From microgravimetry, vibrational spectroscopy, and X-ray diffraction, we find that birnessite intercalates no more than one monolayer of water per interlayer when exposed to water vapor at 25 °C, even near the dew point. Molecular dynamics showed that a single monolayer is an energetica

SUBMITTER: Cheng W 

PROVIDER: S-EPMC7880569 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature