• 文献标题:   Laser Photoreduction of Graphene Aerogel Microfibers: Dynamic Electrical and Thermal Behaviors
  • 文献类型:   Article
  • 作  者:   HUNTER N, KARAMATI A, XIE YS, LIN H, WANG XW
  • 作者关键词:   graphene aerogel, photoreduction, microfiber, thermal diffusivity, electrical resistivity
  • 出版物名称:   CHEMPHYSCHEM
  • ISSN:   1439-4235 EI 1439-7641
  • 通讯作者地址:  
  • 被引频次:   2
  • DOI:   10.1002/cphc.202200417 EA SEP 2022
  • 出版年:   2022

▎ 摘  要

This work reports the dynamic behaviors of graphene aerogel (GA) microfibers during and after continuous wave (CW) laser photoreduction. The reduction results in one-order of magnitude increase in the electrical conductivity. The experimental results reveal the exact mechanisms of photoreduction as it occurs: immediate photochemical removal of oxygen functional groups causing a sharp decrease in electrical resistance and subsequent laser heating that facilitates thermal rearrangement of GO sheets towards more graphene-like domains. X-ray and Raman spectroscopy analysis confirm that photoreduction removes virtually all oxygen and nitrogen containing functional groups. Interestingly, a dynamic period immediately following the end of laser exposure shows a slow, gradual increase in electrical resistance, suggesting that a proportion of the electrical conductivity enhancement from photoreduction is not permanent. A two-part experiment monitoring the resistance changes in real-time before and after photoreduction is conducted to investigate this critical period. The thermal diffusivity evolution of the microfiber is tracked and shows an improvement of 277 % after all photoreduction experiments. A strong linear coherency between thermal diffusivity and electrical conductivity is also uncovered. This is the first known work to explore both the dynamic electrical and thermal evolution of a GO-based aerogel during and after photoreduction.