Structure-property relationships of nanostructured iron manganese oxides: from synthesis to electrochemical properties
Nanostructured manganese oxides (MnOx) can be applied in energy storage and catalysis. Thus, structure-property relationships are key for the rational design of efficient MnOx functional nanomaterials. In this project, we stablish correlations between the local structure and chemistry and the electrochemical properties of iron manganese oxide (FexMn1-xO2) nanosheets, nanowires and nanocones.
MnOx have drawn interest due to their low price, abundance, stability and variety of morphologies. They can be applied in energy storage devices (e.g. batteries, supercapacitors) or as catalysts for H2 fuel production or growth of carbon nanotubes. However, their properties are strongly dependent on crystal structure, morphology, and composition (e.g. Fe increases the conductivity of MnOx), thus requiring systematic studies to determine structure-property relationships.
This project focuses on establishing structure-property relationships for various iron manganese oxides (FexMn1-xO2) nanomorphologies, namely nanosheets, nanowires and nanocones. Our approach explores novel wet-chemistry syntheses routes to allow tuning of structure, porosity and introduction of dopants in the nanomaterials. The synthesis is combined with an in-depth characterization by scanning and transmission electron microscopy (SEM, TEM), energy dispersive X-ray (EDS), electron energy loss spectroscopy (EELS) and Raman spectroscopy to unravel structural and chemical features down to atomic resolution. Finally, the electrochemical properties are assessed through cyclic voltammetry and identical location TEM. These systematic studies allow to correlate the effect of the crystal structure, morphology and chemistry of FexMn1-xO2 materials with their electrochemical activity and stability as supercapacitors and electrocatalysts.