Solution plasma synthesis of birnessite-type MnO2/carbon composites: support-dependent surface chemistry and alkaline oxygen reduction performance
- 1Materials Science and Engineering, Graduate School of Engineering and Science, Shibaura Institute of Technology Toyosu, Koto-Ku Tokyo 135-8548 Japan.
- 2Department of Materials Engineering, Faculty of Engineering, Kasetsart University Bangkok 10900 Thailand.
- 3College of Engineering, Shibaura Institute of Technology Toyosu, Koto-Ku Tokyo 135-8548 Japan [email protected].
Abstract
Here, CNT-supported and Ketjen Black (KB)-supported composites were synthesized by a solution plasma process (SPP) for 10 min without external heating. XRD and SEM indicate the formation of poorly crystalline birnessite-type oxide on both supports, with support- and precursor-dependent deposition characteristics. The supports also differ in surface area, surface chemistry, and pretreatment; consequently, this comparison does not isolate morphology as an independent variable. XPS indicates differences in the Mn spectral response, whereas the direction of interfacial charge transfer and the identity of a low-binding-energy C 1s contribution remain unresolved. In O₂-saturated 0.1 M KOH, KB-M1 exhibited the highest onset potential among the synthesized composites, 0.873 V vs. RHE, and a geometric current density of -4.21 mA cm⁻² at 0.464 V. CNT-M0.5 showed the highest onset potential within the CNT series, 0.804 V. CNT-M0.5 and KB-M1 retained 93.1% and 90.8% of their initial currents, respectively, after 20 000 s of chronoamperometry. The results demonstrate a short SPP route and support-dependent alkaline ORR behavior, while highlighting the need for matched controls and interface-specific measurements to resolve the underlying mechanisms.
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BibTeX
@article{yamamoto2026solution,
title = {{Solution plasma synthesis of birnessite-type MnO2/carbon composites: support-dependent surface chemistry and alkaline oxygen reduction performance}},
author = {Kouki Yamamoto and Kentaro Ogihara and Taiyo Suzuki and Toshiki Iwato and Gasidit Panomsuwan and Takahiro Ishizaki},
journal = {RSC advances},
year = {2026},
month = nov,
doi = {10.1039/d6ra06750f},
url = {https://europepmc.org/article/PMC/PMC13725866},
note = {CC BY},
}
RIS
TY - JOUR
TI - Solution plasma synthesis of birnessite-type MnO2/carbon composites: support-dependent surface chemistry and alkaline oxygen reduction performance
AU - Kouki Yamamoto
AU - Kentaro Ogihara
AU - Taiyo Suzuki
AU - Toshiki Iwato
AU - Gasidit Panomsuwan
AU - Takahiro Ishizaki
PY - 2026
DA - 2026/11/02
JO - RSC advances
DO - 10.1039/d6ra06750f
UR - https://europepmc.org/article/PMC/PMC13725866
AB - Here, CNT-supported and Ketjen Black (KB)-supported composites were synthesized by a solution plasma process (SPP) for 10 min without external heating. XRD and SEM indicate the formation of poorly crystalline birnessite-type oxide on both supports, with support- and precursor-dependent deposition characteristics. The supports also differ in surface area, surface chemistry, and pretreatment; consequently, this comparison does not isolate morphology as an independent variable. XPS indicates differences in the Mn spectral response, whereas the direction of interfacial charge transfer and the identity of a low-binding-energy C 1s contribution remain unresolved. In O₂-saturated 0.1 M KOH, KB-M1 exhibited the highest onset potential among the synthesized composites, 0.873 V vs. RHE, and a geometric current density of -4.21 mA cm⁻² at 0.464 V. CNT-M0.5 showed the highest onset potential within the CNT series, 0.804 V. CNT-M0.5 and KB-M1 retained 93.1% and 90.8% of their initial currents, respectively, after 20 000 s of chronoamperometry. The results demonstrate a short SPP route and support-dependent alkaline ORR behavior, while highlighting the need for matched controls and interface-specific measurements to resolve the underlying mechanisms.
SN - 2046-2069
ER -