▎ 摘　　要

Surface adsorption of small molecules modulates both optical and electronic structure, which is beneficial for different applications. The molecular adsorption of halogens X-2 (X-2 = I-2, B(r)2, Cl-2, and F-2) was investigated using density functional theory and the dispersion (Wb97xd) module. The electronic structure and optical properties of the pristine graphene oxide (GO) and its molecular complexes with halogens (GOI(2), GOBr(2), GOCl(2), and GOF(2)) are explored. The adsorption of X2 (X-2 = I-2, Br-2, and Cl-2) molecules were stabilized by non-covalent lone pair-pi bonding, (O)lp... pi, interactions and pi-pi interactions. The F-2 molecule were stabilized by lone pair-pi bonding, (O) lp... pi, as well as halogen bonding (XB). The GOX2 complexes were energetically stable and optically red shifted in polar solvents. The simulated optical absorption spectra at TD-DFT calculations of GOX2 complexes and TDOS uncover the presence of intermediate sates in the energy gap region, which is beneficial for harvest of visible light and photocatalysis.