Event date:
Mar 3 2021 3:00 pm

Nanostructured Carbons Containing FeNi/NiFe2O4 Supported Over N-doped Carbon Nanofibers for Oxygen Reduction and Evolution Reactions

Iram Aziz
The need to replace precious metals such as platinum, ruthenium and iridium with non-precious metal-based electrocatalysts has led to the development of metal containing carbonaceous nanostructures with high durability and low cost. These primarily find use for catalyzing oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) for fuel-cell and metal-air battery applications. In this investigation, two different morphologies of FeNi/NiFe2O4 supported over hierarchical N-doped carbons were achieved via carbonization of the polymer nanofibers. By controlling the ratio of metal salts to melamine, a mixture of carbon nanotubes (CNTs) and graphene nanotubes (GNTs) supported over carbon nanofibers (CNFs) with spherical FeNi encapsulated at the tips (G/CNT@NCNF) were fabricated. By increasing the ratio, graphene sheets wrapped CNFs with embedded needle-like FeNi (GS@NCNF) were obtained. The effect of structure on catalytic performance of the prepared nanostructures were evaluated for ORR and OER. For ORR, G/CNT@NCNF showed significant catalytic behavior with an onset potential of 0.948 V, vs. reversible hydrogen electrode (RHE) and 0.85 V onset potential for GS@NCNF. A higher current density than Pt/C beyond 0.720 V was also observed due to the carbon nanofiber support with superior stability and methanol tolerance to Pt/C in alkaline media. For OER, GS@NCNF shows the lowest over-potential of 230 mV at 10 mA cm-2 but show low stability and high Tafel slope as compared to G/CNT@NCNF. The catalytic activity of acid treated G/CNT@NCNF and GS@NCNF were also studied and significant decrease in activity was observed. Such high activities reported herein are due to the synergistic effects of the bimetallic nanoparticles encapsulated at CNT tips and N-doped carbons with unique hierarchical structures and the desired defects.

Iram Aziz is a PhD candidate for Chemistry and is going to present her research on the topic of “Nanostructured Carbons Containing FeNi/NiFe2O4 Supported Over N-doped Carbon Nanofibers for Oxygen Reduction and Evolution Reactions”. She has been working under the guidance and supervision of Dr. Salman Noshear Arshad. Meanwhile the committee members are Dr. Falak Sher and Dr. Basit Yameen from the Chemistry department at SBASSE LUMS.

This session is going to be conducted online via Zoom on Wednesday, 3rd March, 2021 at 3:00 PM.


Reference: Iram et al. RSC Advances 9, 36586-36599, 2019.