▎ 摘　　要

Basic divalent sulfide species exhibit unique chemical activity in that they react with organic matter and function as a redox reagent. Herein, graphene oxide (GO) was modified by basic divalent sulfide species, and the modified materials were characterized by FT-IR spectra, XRD, UV-Vis, SEM, HRTEM, XPS, TG-MS analysis, Raman spectroscopy and electrical conductivity measurements. The results indicated that basic divalent sulfide species removed the abundant oxygen-containing groups from the basal plane of GO, in which the pi-conjugated structure was largely restored. The basic divalent sulfide species also react with marginal oxygen-containing groups and were doped into GO to form large-area pi-conjugated structures, resulting in the high electrical conductivity of sulfur-modified GO (SGO). TG-MS analysis showed that the basic divalent sulfide in SGO can be removed by heating, which provides a new method for preparing larger-area graphene sheets from GO with a smaller average size. In addition, SGO prepared without annealing displayed better performance in converting fructose, glucose, cellobiose and cellulose to 5-hydroxymethylfurfural (HMF) because it retained some acidic marginal oxygen-containing groups and basic divalent sulfide species.