Speakers
Description
Various approaches are available for the nitrogen (N) doping of graphene oxide, but there needs to be more understanding of the N insertion mechanism using melamine as a precursor. N-doped graphene is widely recognized for its applications in oxygen reduction reactions (ORR). This study explored the mechanism of N insertion into graphene layers and investigated the influence of oxygen in this process. Furthermore, we examined the mechanisms of N doping and desorption at different temperatures (700, 800, 900, and 1000 °C). After thermal treatment at 900 °C for 2 hours, we assessed the selectivity of nitrogenated species and their impact on ORR effectiveness. Three types of materials were analyzed: a raw sample treated at 700 °C for 30 minutes, a sample treated at 900 °C for 30 minutes, and a sample subjected to sequential treatment first at 700 °C for 30 minutes, followed by heating at 900 °C for 2 hours. The total nitrogen content in each sample was approximately 21, 9, and 8 nitrogen atoms per 100 carbon atoms, respectively. Notably, the samples treated at 900 °C had similar nitrogen and nitrogen species content, but the NP species specifically decreased compared to the other samples, suggesting a potentially significant role in the activity. Density functional theory (DFT) calculations were performed to elucidate the O and N variations upon the insertion mechanisms.
This work was supported by
DGAPA-UNAM project IN105722. Calculations were performed in the DGTIC-UNAM Supercomputing Center projects LANCAD-UNAM-DGTIC-051 and LANCAD-UNAM-DGTIC-382, J.I.P.O acknowledge DGAPA-UNAM for the postdoctoral position.
Reference
Hector Noe Fernandez-Escamilla, et.al. Understanding the selectivity of the oxygen reduction reaction at the atomistic level on nitrogen-doped graphitic carbon materials. Advanced Energy Materials, 11(3):2002459, 2021.
| Keywords | graphene oxide, N-doping, ORR, DFT |
|---|---|
| Author approval | I confirm |
| Author will attend | I confirm |
