Synthesis of graphene oxide using boric acid in hummers method.

An improved Hummers method for preparing graphene oxide (GO) has been developed using boric acid (H 3 BO 3) to replace sodium nitrate (NaNO 3). This modification can shorten the reaction time to 1 h at room temperature, inhibit effectively the generation of carbonyl and carboxyl groups, eliminate the emission of toxic gases of nitrogen dioxide (NO 2) and dinitrogen tetroxide (N 2 O 4), and increase the yield by 10% in GO production. While the morphology of GO synthesized by the modified Hummers method, observed by SEM and TEM, is similar to that of the traditional Hummers method, Raman analysis found that the GO synthesized herein has fewer structural defects than the traditional Hummers method. XPS analysis indicated that boric acid had a significant inhibitory effect on the carbonyl groups. Boric acid could mitigate the formation of carbonyl groups, but did not prevent the formation of carbonyl groups. The Hummers method utilizes H 3 BO 3 instead of NaNO 3 to protect the functional groups in the basal plane of GO, reduce structural defects, and inhibit the generation of carbonyl and carboxyl functional groups. [Display omitted] [ABSTRACT FROM AUTHOR]