Graphite powder

Exfoliation of GO was performed in the present work (Figure S2 and Table S2). Edge-oxidized graphene oxide (Aldrich, Graphene oxide powder, 4–10% oxidized) was used as purchased without purification. Graphite (Fujifilm-Wako, Graphite powder, 98%, Particle size (pass 45 μm)) was used as a reference. GO powder (30 mg) was dispersed in 12 cm³ of 2-propanol (Kanto, 99.7%), 2-butanol (Kanto, 99.0%), 1-decanol (Kanto, 95.0%), 1-octanol (Junsei, 98.0%), 1-pentanol (TCI, 99.0%), purified water, formamide (Kanto, 98.0%), nitrobenzene (Kanto, 99.5%), dimethyl sulfoxide (DMSO, Kanto, 99.0%), and 1,1,2,2-tetrabromoethane (TCI, 98.0%) for 5 days at 60°C with stirring at 300 rpm. The dispersion liquid was filtered to remove the unexfoliated precursors. The detailed characterization of the GO nanosheets was described in Figure S2 and Table S2. The layered structures were analyzed by X-ray diffraction with Cu-Kα radiation (XRD, Bruker D8 Advance). The particle-size distribution of the nanosheet colloid was measured by dynamic light scattering (DLS, Otsuka Electronics, ELSZ-2000ZS).

Graphite powder, potassium chlorate, sulfuric acid, KMnO₄, hydrazine monohydrate and thionyl chloride were purchased from Wako Chemical Co. Ltd. (Osaka, Japan). 94% Fuming nitric acid, hydrogen peroxide and N,N-dimethylformamide (DMF) were obtained from Nakarai tesque Co. Ltd. (Kyoto, Japan).

All chemicals were obtained from commercial suppliers and were used without further purification. Iron phthalocyanine (FePc, 90%, Sigma-Aldrich), chloroform (99.0%, Wako), graphite powder (98.0%, Wako), and DMF (99.0%, Wako) were used.