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Shimoyama, Iwao; Baba, Yuji
Carbon, 98, p.115 - 125, 2016/03
Times Cited Count：34 Percentile：72.68(Chemistry, Physical)The amounts of adsorbed thiophene were compared among phosphorus- and nitrogen-doped graphite and graphite damaged by Ar
irradiation to clarify the influence of heteroatom doping on the adsorptive desulfurization properties of 
-conjugated carbon materials. On the basis of thiophene coverages estimated from X-ray photoelectron spectroscopy, Phosphorus-doped graphite had an adsorption ability that was 10-20 times larger than that of Nitrogen-doped graphite, indicating that the adsorptive desulfurization property of carbon largely depends on dopant atoms. Polarization dependent analysis using near-edge X-ray absorption fine structure spectroscopy was used to distinguish the configurations at dopant sites, indicating that the curved structures of phosphorus sites exhibited approximately 10 times greater adsorption abilities when compared with the planar structures. Theoretical simulation using molecular orbital calculations indicated different dopant effects between phosphorus and nitrogen along with different thiophene adsorption behaviors between planar and curved structures. Finally, experimental thiophene desorption results obtained at different temperatures revealed an advantage of phosphorus doping for reactivation.
Ishihara, Masahiro; Hanawa, Satoshi; Sogabe, Toshiaki; Tachibana, Yukio; Iyoku, Tatsuo
Materials Science Research International, 10(1), p.65 - 70, 2004/04
no abstracts in English
Oku, Tatsuo*; Baba, Shinichi
Tanso, 2002(202), p.90 - 95, 2002/05
no abstracts in English
; *; Araki, Masanori; Nakamura, Kazuyuki; Akiba, Masato
Journal of Nuclear Materials, 258-263, p.318 - 322, 1998/00
Times Cited Count：8 Percentile：57.28(Materials Science, Multidisciplinary)no abstracts in English
Matsuo, Hideto
Shin, Tanso Zairyo Nyumon, 0, p.182 - 188, 1996/00
no abstracts in English
Matsuo, Hideto
JAERI-M 91-090, 15 Pages, 1991/06
no abstracts in English
Matsuo, Hideto
Tanso, 0(150), p.290 - 302, 1991/00
no abstracts in English
Matsuo, Hideto; Saito, Tamotsu; Imai, Hisashi
JAERI-M 89-080, 18 Pages, 1989/06
no abstracts in English
Saeki, Masakatsu
Kaku Yugoro, 19, p.6 - 10, 1987/00
no abstracts in English
; ;
JAERI-M 84-213, 12 Pages, 1984/11
no abstracts in English
;
Tanso, 112, p.2 - 5, 1983/00
no abstracts in English
; ; ;
JAERI-M 8857, 14 Pages, 1980/05
no abstracts in English
; ; ;
JAERI-M 8561, 21 Pages, 1979/11
no abstracts in English
; ; ; ; *
JAERI-M 8551, 15 Pages, 1979/11
no abstracts in English
; ;
Tanso, (72), p.14 - 20, 1973/00
no abstracts in English
Zairyo, 14(137), p.91 - 100, 1965/00
no abstracts in English
Ota, Tomonori*; Hagiwara, Tokio*; Sugimoto, Masaki; Yamamoto, Shunya; Koshikawa, Hiroshi; Yamaki, Tetsuya
no journal, ,
Nitrogen (N)-doped carbon-based electrocatalysts are expected as a platinum alternative material for cost reduction of polymer electrolyte membrane fuel cells. However, nobody has not yet established the method of introducing N atoms in a graphene structure at high concentrations. Therefore, our purpose is to propose a new method of N doping using electron beam irradiation at high temperatures in an ammonia atmosphere. We developed here a sample chamber with a heating device, gas inlet and outlet, which made it possible to perform the irradiation without any temperature change. As a result, the phenolic resin, that is, a source of carbon-based electrocatalysts was irradiated with 2 MeV electrons at a dose rate of 2 kGy/s while being maintained at 300 
C with a high precision as 
2 C.
Ota, Tomonori*; Yamaki, Tetsuya; Sugimoto, Masaki; Yamamoto, Shunya; Koshikawa, Hiroshi; Hagiwara, Tokio*
no journal, ,
Nitrogen-doped carbon-based catalysts are expected as Pt alternatives, and however there have been so far no established methods to introduce N atoms into graphene structures. Thus, we report N doping in carbon-based catalysts by electron beam (EB) irradiation in ammonia (NH
). A precursor was phenolic resin or its mixture with 5 or 10 wt% cobalt(II) chloride (CoCl
); it was then irradiated with 2 MeV electron beam up to a dose of 6 MGy in 1 vol% NH at 400C. This irradiated powder was carbonized in an Ar atmosphere at 800C for 1 h. An N-doping level reached an atomic concentration of ca. 0.5% when 5 wt% CoCl was mixed in the precursor.
Sugimoto, Masaki; Ota, Tomonori*; Yamamoto, Shunya; Koshikawa, Hiroshi; Yamaki, Tetsuya; Hagiwara, Tokio*
no journal, ,
no abstracts in English
Shimoyama, Iwao; Baba, Yuji
no journal, ,
Carbon alloy is a series of materials prepared by heteroatom doping in -conjugated carbon materials and recently attracts much attention due to some functionalities such as catalytic activity. We study the changes of two functionalities, catalytic activity on oxygen reduction reaction and adsorptive desulfurization property for thiophene, induced by phosphorus doping in graphite. The configurations at phosphorus sites were investigated by near-edge X-ray absorption fine structure spectroscopy and molecular orbital (MO) calculations, and we clarified that phosphorus sites formed planar and curved configurations depending on substrate temperature during ion doping. We also found that curved phosphorus-doped graphite had better catalytic activity and desulfurization property when curved configuration was preferentially formed. Comparison between phosphorus and nitrogen dopings suggests that phosphorus is superior to nitrogen with regard to adsorptive desulfurization. We interpreted these experimental results based on MO calculations and clarified the role of phosphorus as a dopant.
