Selective Reduction Mechanism of Graphene Oxide Driven by the Photon Mode versus the Thermal Mode

Masaki Hada, Kiyoshi Miyata, Satoshi Ohmura, Yusuke Arashida, Kohei Ichiyanagi, Ikufumi Katayama, Takayuki Suzuki, Wang Chen, Shota Mizote, Takayoshi Sawa, Takayoshi Yokoya, Toshio Seki, Jiro Matsuo, Tomoharu Tokunaga, Chihiro Itoh, Kenji Tsuruta, Ryo Fukaya, Shunsuke Nozawa, Shin Ichi Adachi, Jun TakedaKen Onda, Shin Ya Koshihara, Yasuhiko Hayashi, Yuta Nishina

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3 Citations (Scopus)

Abstract

A two-dimensional nanocarbon, graphene, has attracted substantial interest due to its excellent properties. The reduction of graphene oxide (GO) has been investigated for the mass production of graphene used in practical applications. Different reduction processes produce different properties in graphene, affecting the performance of the final materials or devices. Therefore, an understanding of the mechanisms of GO reduction is important for controlling the properties of functional two-dimensional systems. Here, we determined the average structure of reduced GO prepared via heating and photoexcitation and clearly distinguished their reduction mechanisms using ultrafast time-resolved electron diffraction, time-resolved infrared vibrational spectroscopy, and time-dependent density functional theory calculations. The oxygen atoms of epoxy groups are selectively removed from the basal plane of GO by photoexcitation (photon mode), in stark contrast to the behavior observed for the thermal reduction of hydroxyl and epoxy groups (thermal mode). The difference originates from the selective excitation of epoxy bonds via an electronic transition due to their antibonding character. This work will enable the preparation of the optimum GO for the intended applications and expands the application scope of two-dimensional systems.

Original languageEnglish
Pages (from-to)10103-10112
Number of pages10
JournalACS nano
Volume13
Issue number9
DOIs
Publication statusPublished - Sep 24 2019

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All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

Cite this

Hada, M., Miyata, K., Ohmura, S., Arashida, Y., Ichiyanagi, K., Katayama, I., ... Nishina, Y. (2019). Selective Reduction Mechanism of Graphene Oxide Driven by the Photon Mode versus the Thermal Mode. ACS nano, 13(9), 10103-10112. https://doi.org/10.1021/acsnano.9b03060