ENHANCING OXYGEN EVOLUTION ACTIVITY OF NI, FE OXIDES USING NITROGEN PLASMA
The oxygen evolution reaction (OER) is a vital half-reaction for clean energy applications, such as water splitting and rechargeable metal-air batteries. However, this reaction suffers from sluggish kinetics due to high overpotential. To date, the most effective OER catalysts are RuO2 and IrO2. H...
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| Format: | Theses |
| Language: | Indonesia |
| Online Access: | https://digilib.itb.ac.id/gdl/view/72994 |
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| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | The oxygen evolution reaction (OER) is a vital half-reaction for clean energy
applications, such as water splitting and rechargeable metal-air batteries.
However, this reaction suffers from sluggish kinetics due to high overpotential. To
date, the most effective OER catalysts are RuO2 and IrO2. However, their relatively
high-cost raw material hinders their practical application. Therefore, we need to
develop alternative materials to replace these noble metal-based catalysts.
The search for non-noble metal electrocatalysts has been extensively studied. In
this study, Ni, and Fe oxides dispersed on carbon framework have been synthesized.
The metal-organic framework precursors were synthesized using the coprecipitation
method. The precursors were then calcined at 600oC to obtain the
corresponding metal oxides supported on a carbon framework.
In this study, the effect of the Ni to Fe ratio has been studied. The best performing
OER catalyst is Ni, Fe oxides/C (1:1). This sample possesses the highest NiFe2O4
content which has a theoretical eg occupancy of ~1.3. Which is close to the ideal
OER electrocatalyst (~1.25).
The nitrogen plasma treatment was done and shown to enhance the electrocatalytic
performance of the samples, increasing its ORR onset potential significantly by
0.09V. This is due to etching and destroying ?-orbital conjugation of chemically
stable sp2 hybridization. The nitrogen plasma treatment can also dope the carbon
framework and add more pyridinic-N and pyrrolic-N sites which also increase its
electrocatalytic activity due to the conjugation of ?-orbital and the nitrogen lone
pair electron.
Lastly, the effect of different ligands has also been studied. The N-doped carbon
framework showed superior performance (higher power density) compared to bare
carbon due to its increased conductivity. |
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