TY  - JOUR
T1  - Plasma surface modification of single-atom Fe active sites on nano-sized graphene platelets for advanced oxygen reduction reaction
A1  - Lee, Sungho
A1  - Kim, Seonghee
A1  - Lee, Jin Hong
A1  - Choi, Heechae
A1  - Takeuchi, Nozomi
A1  - Li, Oi Lun
Y1  - 2022///
KW  - Plasma modification
KW  - single-atom doped graphene
KW  - oxygen reduction reaction
KW  - electrocatalysts
JF  - International Journal of Plasma Environmental Science and Technology
VL  - 16
IS  - 3
SP  - e03002
EP  - e03002
DO  - 10.34343/ijpest.2022.16.e03002
UR  - http://ijpest.com/Contents/16/3/e03002.html
N2  - https://doi.org/10.34343/ijpest.2022.16.e03002 Plasma surface modification of single-atom Fe active sites on nano-sized graphene platelets for advanced oxygen reduction reaction Sungho Lee1, *, Seonghee Kim1, *, Jin Hong Lee2, Heechae Choi3, Nozomi Takeuchi4, **, Oi Lun Li1, ** * Co-first authors having the equal contribution to this paper. ** The authosr to whom correspondence should be addressed. 1 School of Materials Science and Engineering, Pusan National University, South Korea 2 School of Chemical Engineering, Pusan National University, South Korea 3 Institute of Inorganic Chemistry, University of Cologne, Germany 2 4Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, Japan Abstract Single-atom Fe-doped carbon nanographene demonstrates promising results as an oxygen reduction reaction (ORR) electrocatalyst in fuel cells and rechargeable metal-air batteries. In this study, plasma-in-liquid process was applied to modify the surface of graphene nanoplatelet (GNP) with iron (II) Phthalocyanine as the Fe precursor and mixed into 1- Methyl-2-pyrrolidone (solvent) for 20 minutes. During the plasma modification, tiny discharge bubbles were observed, where the emission of C2, CH, CN, and H radicals were identified by the optical emission spectrum. From the highresolution TEM and the corresponding EDS elemental mapping images, the isolated Fe were successfully anchored as single-atom on GNP between 0.50 ~ 0.82 at.%. The ORR activity greatly enhanced after plasma modification, where the single-atom Fe-doped GNP demonstrated extremely high onset potential (Eonset) and half-wave potential (E1/2) of 0.95 - 0.98 and 0.87 V - 0.90 V vs RHE, correspondingly. Most importantly, plasma-modified Fe-GNP catalysts showed superior ORR catalytic activity compared to other single-atom Fe with similar metal loading catalysts reported in recent studies. The unique plasma-induced chemical reaction via active radicals not only successfully anchored atomic Fe onto the surface but also created certain defects of GNP, which created a synergic effect on the ORR catalytic activities.
ER  -