▎ 摘　　要

Two-dimensional carbons synthesis through sustainable bio-manufacturing methods has attracted much attention in the past decade. This process facilitates low cost and facile manufacturing of porous carbon materials with specific characteristics, as well as chemical functions that differ from their bulk counterparts due to the low dimensionality. Herein, a unique graphene-like carbon framework composed of three-dimensionally interconnected nanosheets has been successfully fabricated via carbonization of a biomass precursor guanine and colloidal silica. The obtained two-dimensional carbon materials, consisting of carbon nanosheets with varying sizes, can provide huge exposed areas. Owing to the merits of insitu nitrogen-doping, particularly the optimization of nitrogen species and significant improvement in porosity, the sample GHS-1000-2.5 delivers the outstanding electrochemical activity towards oxygen reduction reaction in both acid and alkaline conditions, which are comparable to the commercial Pt/C catalyst and show even better performance under the same conditions. This highly efficient, facile and low-cost strategy is expected to meet the requirements for the commercialization for fuel cells.