▎ 摘　　要

The ongoing revolution in optoelectronics based on graphene and graphene oxide (GO) demands the comprehension of reduction mechanisms. One of the most feasible reduction methods for GO is photo-reduction, which has been widely used and investigated. Here, from the perspective on the fluorescence evolution process of photo-reduced GO, we have studied the mechanisms of visible/ultraviolet (UV) photo-reduced GO in detail by steady-state photoluminescence spectroscopy and femtosecond transient absorption spectroscopy. It demonstrates that the oxygen-containing functional groups (OFGs) in sp(3) domains of GO are initially reduced by visible light, while the OFGs in the boundary between neighboring sp(2)-and sp(3)-hybridized domains of GO prefer to be reduced by UV light. Raman spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy further prove the partial elimination of OFGs and the reconstruction of the C = C bonds, despite the GO reduced by visible light or UV light. Our work provides insight into the mechanisms of visible/UV photo-reduced GO. (C) 2017 Optical Society of America