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Photochemical Oxidative Growth of Iridium Oxide Nanoparticles on CdSe@CdS Nanorods
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IrO2 Oxygen Evolution Catalysts Prepared by an Optimized Photodeposition Process on TiO2 Substrates
Angeliki Banti1, Christina Zafeiridou1, Michail Charalampakis2
1Physical Chemistry Laboratory, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
Molecules (Basel, Switzerland)
|May 25, 2024
Summary
Highly active iridium oxide/titanium dioxide (IrO2/TiO2) catalysts were developed for the oxygen evolution reaction (OER) in acidic media. These IrO2/TiO2 electrodes show excellent performance for green hydrogen production via water electrolysis.
Area of Science:
- Materials Science
- Electrochemistry
- Catalysis
Background:
- Developing efficient oxygen evolution reaction (OER) catalysts with low precious metal loadings is crucial for water electrolysis and green hydrogen production.
- Stable and conductive support materials are essential for high-performance OER catalysts, especially in acidic media.
- Combining stable titanium dioxide (TiO2) with active iridium oxide (IrO2) offers a promising strategy for advanced OER catalysts.
Purpose of the Study:
- To synthesize highly active IrO2/TiO2 electrodes for OER in acidic media using UV photodeposition.
- To investigate the effect of preparation methods on IrO2 nanoparticle dispersion and catalytic performance.
- To evaluate the electrocatalytic activity and stability of the developed catalysts for water electrolysis applications.
Main Methods:
- TiO2 powders (commercial and lab-made) were decorated with IrO2 nanoparticles via UV photodeposition.
- Various characterization techniques including TEM, EDS, FESEM, XPS, and XRD were employed to analyze the catalyst structure.
- Electrocatalytic performance was assessed using cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) in 0.1 M HClO4.
Main Results:
- Optimized UV photodeposition (without methanol) resulted in well-dispersed IrO2 nanoparticles on TiO2 supports.
- All synthesized TiO2-based catalysts demonstrated superior mass-specific OER activity compared to unsupported IrO2.
- The best IrO2/TiO2 catalysts achieved 100 mA/mg_Ir at an overpotential of 243 mV, with good medium-term stability shown by chronoamperometry.
Conclusions:
- IrO2/TiO2 composite materials are highly effective OER catalysts in acidic media, outperforming commercial IrO2.
- The UV photodeposition method provides a controllable route for synthesizing efficient and stable IrO2/TiO2 electrocatalysts.
- These findings highlight the potential of IrO2/TiO2 electrodes for efficient green hydrogen production through water electrolysis.
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