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Manganese Oxide Nanoparticle Synthesis by Thermal Decomposition of ManganeseII Acetylacetonate
Published on: June 18, 2020
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Cosputtered Calcium Manganese Oxide Electrodes for Water Oxidation
Hamed Simchi1, Kayla A Cooley1, Jonas Ohms2
1Department of Materials Science and Engineering and Materials Research Institute, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
Inorganic Chemistry
|December 29, 2017
Summary
Annealing calcium manganese oxide films enhances their catalytic activity for the oxygen evolution reaction (OER). Calcium incorporation improves manganese oxide electrocatalyst performance for water oxidation.
Area of Science:
- Materials Science
- Electrochemistry
- Catalysis
Background:
- Developing efficient electrocatalysts for the oxygen evolution reaction (OER) is crucial for water splitting technologies.
- Manganese oxides are abundant and non-toxic alternatives to precious metal catalysts.
- Understanding the role of dopants like calcium in manganese oxide catalysts is key to optimizing their performance.
Purpose of the Study:
- To prepare and evaluate calcium manganese oxide (CaMnxOy) films as potential catalysts for the oxygen evolution reaction (OER).
- To investigate the effect of annealing on the structural and electrochemical properties of CaMnxOy films.
- To determine if calcium incorporation enhances the OER activity of manganese oxide electrocatalysts.
Main Methods:
- Cosputter deposition of Mn and CaMnO3 targets to create CaMnxOy films.
- Characterization using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), glancing-incidence X-ray diffraction (GIXRD), and transmission electron microscopy (TEM).
- Electrochemical evaluation including cyclic voltammetry (CV) and long-term electrolysis to assess OER activity and stability.
Main Results:
- As-deposited films showed compact morphology, while annealing at 600 °C induced nanorod formation.
- Annealing increased surface Mn oxidation states and revealed a polycrystalline Mn3O4 component with potential Ca incorporation.
- Annealed CaMnxOy films exhibited a ~15-fold increase in OER current density and good electrochemical stability, with negligible corrosion.
Conclusions:
- Annealing significantly enhances the OER activity of sputter-deposited CaMnxOy films.
- Calcium incorporation demonstrably improves the OER performance of manganese oxide electrocatalysts compared to Ca-free counterparts.
- These findings offer guidance for designing efficient water oxidation electrodes using earth-abundant manganese and calcium.
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