▎ 摘　　要

Transient features of graphene oxide (GO), graphene oxide nanoribbon (GOR) and graphene quantum dot (GQD) have been investigated by femtosecond transient absorption (TA) spectroscopy. It is found that for pristine GO and HNO3-/NaOH-treated GO, a hybrid sp(2)/sp(3) state at about 430 nm (similar to 2.88 eV) always appears. However, this hybrid state becomes less apparent in GOR, and completely disappears in GQD. It indicates that there are absolutely different electronic structures in GO, GOR and GQD. Furthermore, compared with pristine GO and GQD, GOR presents a faster decay for carrier dynamics. This could be attributed to the relatively weak interaction between the sp(2) domains and sp(3) matrix in GOR, which facilitates the carrier recombination. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.