Language：English   Publisher：The Japan Society of Vacuum and Surface Science  

<p>Single-walled carbon nanotubes(SWCNTs) are promising materials for flexible, lightweight electronic devices. However, previous studies have reported that under ambient environment the system tends to show p-type character due to a hole doping effect by oxygen or water adsorbed onto the surface, making it difficult to obtain the desired properties[1]. Then, it is required to evaluate the amount of the adsorbed oxygen and their electronic state of the SWCNTs under various environmental conditions quantitatively. In this study, we employed ambient pressure X-ray photoemission spectroscopy (AP-XPS) at NanoTerasu BL08U[2], which enables direct evaluation of the amount of absorbed oxygen and their electronic states of SWCNTs in an oxygen atmosphere. The figure below shows the XPS spectra obtained under two conditions: after heating in vacuum at 573 K (<2 x 10^-6 Pa) and cooling to below 373 K to establish the initial state, and during subsequently heating the sample in an oxygen atmosphere (0.1 kPa, 573 K). As a result of fitting of each spectrum, the oxygen-to-carbon ratio (O/C) was increased from 0.037 to 0.053 mol/mol, indicating approximately a 1.5-fold increase in adsorbed oxygen. Furthermore, a low-energy shift in the C1s peak was detected, which is considered to result from the Fermi energy shifting towards the valence band side due to p-type doping. These results confirm a tendency towards p-type behavior due to hole doping by adsorbed oxygen.</p><p></p><p>References</p><p>[1] T. Fujigaya <i>et al</i>., ACS Appl. Nano Mater. <b>2</b>, 4703−4710 (2019).</p><p>[2] T. Wada <i>et al</i>., Appl. Phys. Express <b>18</b>, 036504 (2025).</p>

DOI： 10.14886/jvss.2025.0_2p29

CiNii Research

Publishing type：Research paper (scientific journal)   Publisher：Beilstein Institut  

Lithium ion-endohedral fullerene (Li⁺@C₆₀), a member of the burgeoning family of ion-endohedral fullerenes, holds substantial promise for diverse applications owing to its distinctive ionic properties. Despite the high demand for precise property tuning through chemical modification, there have been only a few reports detailing synthetic protocols for the derivatization of this novel material. In this study, we report the synthesis of Li⁺@C₆₀ derivatives via the thermal [2 + 2] cycloaddition reaction of styrene derivatives, achieving significantly higher yields of monofunctionalized Li⁺@C₆₀ compared to previously reported reactions. Furthermore, by combining experimental and theoretical approaches, we clarified the range of applicable substrates for the thermal [2 + 2] cycloaddition of Li⁺@C₆₀, highlighting the expanded scope of this straightforward and selective functionalization method.

DOI： 10.3762/bjoc.20.58

Other Link： https://www.beilstein-journals.org/bjoc/content/pdf/1860-5397-20-58.pdf