Comparison study of structural and optical properties of boron-doped and undoped graphene oxide films

We prepared boron (B)-doped graphene oxides (G0s) by means of annealing the films, which were obtained from the suspensions of GO and H3BO3 in N,N-Dimethylformamide solvent. The interplanar spacing of as-synthesized GO in X-ray diffraction spectra has been reduced by the thermal annealing at 1100 degrees C. First-order Raman spectra revealed that the intensity ratio of the D and G bands of B-doped GO was significantly lower than those of as-synthesized and annealed GOs, suggesting more graphitization of the B-doped GO due to doping effect. The C1s X-ray photoelectron spectroscopy (XPS) of B-doped GO films not only indicated that considerable amount of functional groups has been removed but also exhibited the peak of C-B band at around 283.7 eV. Additionally, the B1s XPS spectrum of B-doped GOs could be deconvoluted into several peaks centered at 187.2, 188.9, 190.3, 192.0 and 193.7 eV, being attributed to the presence of B atom in B4C, B-sub-C, BC2O, BCO2 and B2O3, respectively. Comparison of the photoluminescence spectra of B-doped GO with that of 1100 degrees C-annealed GO indicated that the overall intensity was decreased, presumably due to the B-induced graphitization. An additional band at around 600-700 nm from B-doped GO is attributed to the generated boron carbide phases. (C) 2012 Elsevier B.V. All rights reserved.This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2012029262 )