Ultrafast Relaxation Dynamics in Graphene Oxide: Evidence of Electron Trapping

Direct Observation of Quantum‐Confined Graphene‐Like States and Novel Hybrid States in Graphene Oxide by Transient Spectroscopy

“…If this universal feature is observed and demonstrated, it will give us a greater understanding of the electronic nature of GO. At the same time, it will also be remarkably different from previous reports in the fi eld of ultrafast spectroscopy for GO, which would usually involve only featureless excited-state absorption signals [36][37][38] or just emission [ 39 ] . According to our transient spectral evolution of GO/rGO, the experimental results about confi ned graphenelike states are highly consistent with previously expected universal features.…”

“…Femtosecond transient absorption spectroscopy is a powerful tool for exploring the hidden information on electronic structure of materials. In previous work, either the excitation in visible range was ignored, [ 36 ] or the probe window was too narrow to observe the full information. [ 37,38 ] On the basis of our wide probe range from entirely visible to near-infrared light, [40][41][42] the femtosecond selective excitation experiments give us amazing results, as shown in Figure 2 a-g. For GO, seven pump wavelengths have been chosen: 330 nm, 400 nm, 460 nm, 510 nm, 560 nm, 600 nm, and 650 nm.…”

Revealing the ultrafast process behind the photoreduction of graphene oxide

“…Although previous ultrafast optical studies [41][42][43][44] have focused on studying the dynamics of graphene, GO and rGO under various conditions (showing the evolution of valence band electrons after their excitation), it is very important for the reader to notice that what we showed here is the dynamics of a non-reversible chemical reaction (GO-rGO) which is a fundamentally different and so far unobserved process. This work demonstrates that the photoinduced transformation of GO to rGO is an indirect process.…”

The phosphorescence and excitation-wavelength dependent fluorescence kinetics of large-scale graphene oxide nanosheets

“…The s 1 ¼ 4.1 ps component was associated with the carrier phonon scattering process for both GO in EtOH and GO-CONH-TPA. 30,31 It was observed that this component was larger than that of the accumulation type samples. 32 The accumulation type samples have a s 1 component smaller than 2.5 ps.…”

“…Our experiments are in accordance with the literature. [30][31][32][33][34][35][36][37] It is noted that GO-CONH-TPA has a much longer component s 4 ¼ 2 ns, which has not been reported in the previous studies. Yu et al were inclined to identify the longest time component associated with the lowest excited state (LUMO) rather than the trap states (>400 ps).…”