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Molecular Potential Structures of Heat-Treated Single-Wall Carbon Nanohorn Assemblies

2001; American Chemical Society; Volume: 105; Issue: 42 Linguagem: Inglês

10.1021/jp010754f

1520-6106

Katsuyuki Murata, Katsumi Kaneko, William A. Steele, F. Kokai, Kunimitsu Takahashi, D. Kasuya, Kaori Hirahara, Masako Yudasaka, Sumio Iijima,

Boron and Carbon Nanomaterials Research

The microporosity of the heat-treated single-wall carbon nanohorn (SWNH) particles is characterized by nitrogen adsorption at 77 K and the molecular potential calculation using the function, which is based on the Lennard-Jones pair potential. The depth difference of the molecular potential for N2 between the SWNH intraparticle pore and the interparticle space is close to 1000 K. Although the SWNH without the heat-treatment has no open intra-nanohorn space, the intraparticle pores open with the high-temperature treatment in O2. The heat-treatment at 693 K opens almost perfectly the intraparticle pores, leading to 0.47 mL g-1 of the micropore volume and 1010 m2 g-1 of the specific surface area. The subtraction of the N2 adsorption isotherm of the SWNH from that of the SWNH treated at 693 K gave the N2 adsorption isotherm only in the intraparticle pore spaces. The adsorption sites derived from the difference adsorption isotherm are assigned to the pores having different interaction potentials.