start-ver=1.4 cd-journal=joma no-vol=8 cd-vols= no-issue=31 article-no= start-page=e202301644 end-page= dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=20230817 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Polymer Template Synthesis of CuOx/Clay Nanocomposites with Controllable CuOx Formation en-subtitle= kn-subtitle= en-abstract= kn-abstract=Metal oxides have the excellent functions including high thermal stability, electrical properties, catalytic performance, and adsorption properties of acid gases such as CO2 via the acid-base interactions. However, they suffer from low reserves, porosity control, and low adsorption efficiency per weight compared with lightweight materials including carbon and silica. To solve these issues, various methods for supporting metal oxides on porous carriers, such as decomposition-precipitation and impregnation, have been investigated, but controlling the formation of metal oxide on clay nanosheets remains as a challenge. Herein, we developed a soft-template method for supporting metal oxide (CuOx) nanoparticles on activated clay nanosheets. The intercalation of polyethyleneimine (PEI)?Cu2+ complexes between the layers of clay nanosheets followed by calcination to construct CuOx and remove the PEI templates afforded CuOx/clay nanocomposites. The constructed CuOx/clay nanocomposites had the close porosity to that of clay. Tuning the Cu2+/PEI ratio in PEI?Cu2+ complex allowed to control CuOx states (loadings, particle sizes, etc.). Tuning of the supporting conditions allowed constructing a structure suitable for CO2 uptake. These findings will contribute to the development of the material science of metal oxide nanoparticles and their hybrid materials in diverse fields including CO2 adsorbents, energy devices, and catalysts. en-copyright= kn-copyright= en-aut-name=TakeuchiYuki en-aut-sei=Takeuchi en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OhkuboTakahiro en-aut-sei=Ohkubo en-aut-mei=Takahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= affil-num=1 en-affil=Inorganic Chemistry Laboratory, Graduate School of Natural Science & Technology, Okayama University kn-affil= affil-num=2 en-affil=Inorganic Chemistry Laboratory, Graduate School of Natural Science & Technology, Okayama University kn-affil= en-keyword=Clay nanosheets kn-keyword=Clay nanosheets en-keyword=CO2 adsorption kn-keyword=CO2 adsorption en-keyword=Metal oxide nanoparticles kn-keyword=Metal oxide nanoparticles en-keyword=Nanocomposites kn-keyword=Nanocomposites en-keyword=Template method kn-keyword=Template method END start-ver=1.4 cd-journal=joma no-vol=629 cd-vols= no-issue= article-no= start-page=238 end-page=244 dt-received= dt-revised= dt-accepted= dt-pub-year=2023 dt-pub=202301 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Acidic layer-enhanced nanoconfinement of anions in cylindrical pore of single-walled carbon nanotube en-subtitle= kn-subtitle= en-abstract= kn-abstract=The adsorption of the nitrate ion by the cylindrical pore of single-walled carbon nanotubes (SWCNT) was found to be aided by an acidic adsorbed layer. Adsorbed water in the vicinity of the pore wall can supply protons through ionization, forming the acidic layer, according to Raman spectra and results of solution pH fluctuations caused by ion species adsorption. Such an acidic adsorbed layer leads to surplus adsorption of anionic species where the adsorbed amount of nitrate ions is much larger than that of cations. Also, we could observe the Raman bands being assignable to the symmetrical stretching mode at an extremely highfrequency region for nano-restricted nitrate ions compared to any other bulk phases. The abnormal band shift of adsorbed nitrate ions indicates that the nitrate ions are confined in the pore under the effects of nanoconfinement by the pore and the strong interaction with the acidic layer in the pore. Our results warn that we have to construct the adsorption model of aqueous electrolytes confined in carbon pores by deliberating the acid layer formed by the adsorbed water. en-copyright= kn-copyright= en-aut-name=OhkuboTakahiro en-aut-sei=Ohkubo en-aut-mei=Takahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=NakayasuHiroki en-aut-sei=Nakayasu en-aut-mei=Hiroki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=TakeuchiYuki en-aut-sei=Takeuchi en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=TakeyasuNobuyuki en-aut-sei=Takeyasu en-aut-mei=Nobuyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KurodaYasushige en-aut-sei=Kuroda en-aut-mei=Yasushige kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=4 en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=5 en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=Proton kn-keyword=Proton en-keyword=Nitrate ion kn-keyword=Nitrate ion en-keyword=Adsorption kn-keyword=Adsorption en-keyword=Confinement kn-keyword=Confinement en-keyword=Micropore kn-keyword=Micropore en-keyword=Nanospace kn-keyword=Nanospace END start-ver=1.4 cd-journal=joma no-vol=51 cd-vols= no-issue=9 article-no= start-page=971 end-page=974 dt-received= dt-revised= dt-accepted= dt-pub-year=2022 dt-pub=20220905 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Polyiodide Production Triggered by Acidic Phase of Aqueous Solution Confined in Carbon Nanospace en-subtitle= kn-subtitle= en-abstract= kn-abstract=Polyiodide species were synthesized by the acceleration of an acidic environment in the nanospace of single-walled carbon nanotubes (SWCNT) with light irradiation. Raman and EXAFS results strongly support the production of polyiodide species after the adsorption of CsI on SWCNT from aqueous solution. Interestingly, the reaction was initiated by the nano-confined acidic phase formed in a basic environment. The acidic phase plays an essential role as an oxidant for the production of the diiodine that is a source of polyiodide. en-copyright= kn-copyright= en-aut-name=OhkuboTakahiro en-aut-sei=Ohkubo en-aut-mei=Takahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=HiranoYuri en-aut-sei=Hirano en-aut-mei=Yuri kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NakayasuHiroki en-aut-sei=Nakayasu en-aut-mei=Hiroki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=KurodaYasushige en-aut-sei=Kuroda en-aut-mei=Yasushige kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= affil-num=1 en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=4 en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= en-keyword=Single-wall carbon nanotube kn-keyword=Single-wall carbon nanotube en-keyword=Adsorption kn-keyword=Adsorption en-keyword=Polyiodide kn-keyword=Polyiodide END start-ver=1.4 cd-journal=joma no-vol=11 cd-vols= no-issue=2 article-no= start-page=838 end-page=846 dt-received= dt-revised= dt-accepted= dt-pub-year=2021 dt-pub=20210104 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Adsorption enhancement of nitrogen gas by atomically heterogeneous nanospace of boron nitride en-subtitle= kn-subtitle= en-abstract= kn-abstract=In this study, porous boron nitride (p-BN) with hexagonal phase boron nitride (h-BN) pore walls was synthesized using high-temperature calcination. Negligible variation in pore-wall structure can be observed in powder X-ray diffraction (XRD) profiles and infrared (IR) spectra. However, a highly stable p-BN with a stable pore structure even at 973 K under the oxidative conditions is obtained when synthesized at higher than 1573 K under nitrogen gas flow. For p-BN, this stability is obtained by generating h-BN microcrystals. Nitrogen adsorption?desorption isotherms at 77 K provide type-IV features and typical adsorption?desorption hysteresis, which suggests micropore and mesopore formation. Moreover, adsorption?desorption isotherms of Ar at 87 K are measured and compared with those of nitrogen. The relative adsorbed amount of nitrogen (i.e., the amount of nitrogen normalized by that of Ar at each relative pressure or adsorption potential value) on p-BN is considerably larger than that on microporous carbon at low-pressure regions, which suggests the existence of strong adsorption sites on the p-BN surface. In fact, the relative number of adsorbed nitrogen molecules to that of Ar on p-BN is, at most, 150%?200% larger than that on microporous carbon for the same adsorption potential state. Furthermore, additional adsorption enhancement to nitrogen between P/P0 = 10?5 and 10?3 can be observed for p-BN treated at 1673 K, which suggests the uniformly adsorbed layer formation of nitrogen molecules in the vicinity of a basal planar surface. Thus, unlike typical nanoporous sp2 carbons, p-BN materials have the potential to enhance adsorption for certain gas species because of their unique surface state. en-copyright= kn-copyright= en-aut-name=KimuraJun en-aut-sei=Kimura en-aut-mei=Jun kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=OhkuboTakahiro en-aut-sei=Ohkubo en-aut-mei=Takahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name= NishinaYuta en-aut-sei= Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=UritaKoki en-aut-sei=Urita en-aut-mei=Koki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=KurodaYasushige en-aut-sei=Kuroda en-aut-mei=Yasushige kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= affil-num=1 en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=2 en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= affil-num=3 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= affil-num=4 en-affil=Graduate School of Engineering, Nagasaki University kn-affil= affil-num=5 en-affil=Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University kn-affil= END start-ver=1.4 cd-journal=joma no-vol=49 cd-vols= no-issue=4 article-no= start-page=1118 end-page=1125 dt-received= dt-revised= dt-accepted= dt-pub-year=2011 dt-pub=201104 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Exfoliated graphene sheets decorated with metal / metal oxide nanoparticles: simple preparation from cation exchanged graphite oxide en-subtitle= kn-subtitle= en-abstract= kn-abstract=We produced carbon hybrid materials of graphene sheets decorated with metal or metal oxide nanoparticles of gold, silver, copper, cobalt, or nickel from cation exchanged graphite oxide. Measurements using powder X-ray diffraction, transmission electron microscopy, and X-ray absorption spectra revealed that the Au and Ag in the materials (Au-Gr and Ag-Gr) existed on graphene sheets as metal nanoparticles, whereas Cu and Co in the materials (Cu-Gr and Co-Gr) existed as a metal oxide. Most Ni particles in Ni-Gr were metal, but the surfaces of large particles were partly oxidized, producing a core-shell structure. The Ag-Gr sample showed a catalytic activity for the oxygen reduction reaction in 1.0 M KOH aq. under an oxygen atmosphere. Ag-Gr is superior as a cathode in alkaline fuel cells, which should not be disturbed by the methanol cross-over problem from the anode. We established an effective approach to prepare a series of graphene-nanoparticle composite materials using heat treatment. en-copyright= kn-copyright= en-aut-name=GotohKazuma en-aut-sei=Gotoh en-aut-mei=Kazuma kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=1 ORCID= en-aut-name=KinumotoTaro en-aut-sei=Kinumoto en-aut-mei=Taro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=FujiiEiji en-aut-sei=Fujii en-aut-mei=Eiji kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=YamamotoAki en-aut-sei=Yamamoto en-aut-mei=Aki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=HashimotoHideki en-aut-sei=Hashimoto en-aut-mei=Hideki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=OhkuboTakahiro en-aut-sei=Ohkubo en-aut-mei=Takahiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=ItadaniAtsushi en-aut-sei=Itadani en-aut-mei=Atsushi kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=KurodaYasushige en-aut-sei=Kuroda en-aut-mei=Yasushige kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= en-aut-name=IshidaHiroyuki en-aut-sei=Ishida en-aut-mei=Hiroyuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=9 ORCID= affil-num=1 en-affil= kn-affil=Okayama Univ affil-num=2 en-affil= kn-affil=Oita Univ affil-num=3 en-affil= kn-affil=Ind Technol Ctr affil-num=4 en-affil= kn-affil=Okayama Univ affil-num=5 en-affil= kn-affil=Okayama Univ affil-num=6 en-affil= kn-affil=Okayama Univ affil-num=7 en-affil= kn-affil=Okayama Univ affil-num=8 en-affil= kn-affil=Okayama Univ affil-num=9 en-affil= kn-affil=Okayama Univ END