Tracking the light-driven layer stacking of graphene oxide

Development of a Multitimescale Time-Resolved Electron Diffraction Setup: Photoinduced Dynamics of Oxygen Radicals on Graphene Oxide

“…The intensity of the (101̅ 0) diffraction peak decreased, and the positions of the (101̅ 0) and (112̅ 0) diffraction peaks shifted toward higher Q-values, reproducing the previous results. Namely, these changes correspond to AB layer stacking 43 and a decrease in the average length of the C−C bonds. 42 This decrease upon femtosecond and nanosecond UV photoexcitation as a function of incident laser fluence is shown in Figure 5c.…”

“…GO is a water-soluble derivative of graphene that has a two-dimensional layer structure with several different oxygen functional groups. − Several important catalytic reactions and antibacterial and antiviral activities occur on the basal plane of GO. − Thermal treatment, UV photoirradiation, and application of reducing agents can easily remove oxygen functional groups from GO and produce water-insoluble reduced GO (rGO). Previously, we reported the structural dynamics of GO during UV-photoirradiation on the picosecond timescale using ultrafast time-resolved electron diffraction measurements, where upon UV photoirradiation, the oxygen atoms in the epoxy functional groups were selectively removed from the basal plane of GO in ∼40 ps. , By tuning the intensity of the pump UV pulse, one of the C–O bonds of the epoxy oxygen was dissociated, and oxygen radicals were generated on the basal plane of GO. These oxygen radicals relaxed to epoxy functional groups before the GO was irradiated with the next pump UV pulse (<1 ms).…”

“…Previously, we reported the structural dynamics of GO during UV-photoirradiation on the picosecond timescale using ultrafast time-resolved electron diffraction measurements, where upon UV photoirradiation, the oxygen atoms in the epoxy functional groups were selectively removed from the basal plane of GO in ∼40 ps. 42,43 By tuning the intensity of the pump UV pulse, one of the C−O bonds of the epoxy oxygen was dissociated, and oxygen radicals were generated on the basal plane of GO. These oxygen radicals relaxed to epoxy functional groups before the GO was irradiated with the next pump UV pulse (<1 ms).…”

Graphene oxide-based large-area dynamic covalent interfaces

“…Similar discussions were extended to layer stacking effects. 72 Furthermore, they developed a multi-timescale, timeresolved electron diffraction setup and achieved an observation of full structural dynamics of oxygen atoms in epoxy: ultraviolet photoexcitation induced oxygen radical formation in several tens of picoseconds and the relaxation back to the initial state within the microsecond timescale. 73 Conceptually, it might be speculated whether the global position variation of chemical compositions can be realized; that is, whether the long-range migration of chemical compositions is possible.…”

“…Similar discussions were extended to layer stacking effects. 72 Furthermore, they developed a multi-timescale, time-resolved electron diffraction setup and achieved an observation of full structural dynamics of oxygen atoms in epoxy: ultraviolet photoexcitation induced oxygen radical formation in several tens of picoseconds and the relaxation back to the initial state within the microsecond timescale. 73…”