The concentration-dependent effect of NaOH on graphene oxide: Revisited as a reducing agent

Prudent knowledge of the factors in the chemical synthesis of reduced graphene oxide (rGO) can provide a considerable impetus for the precise repeatability needed for the technological adoption of graphene nanocomposites. Sodium Hydroxide (NaOH) is a common ingredient in the synthesis of rGO. The paper presents a systematic study of the effect of NaOH concentration on graphene oxide (GO). The threshold value, where NaOH starts acting as a reducing agent, is proposed in the paper. The finding was corroborated based on absorbance maxima obtained from the UV–Visible spectrum (π - π* transitions) and the peak intensity ratio of Raman spectra. The results indicate that NaOH has a remarkable role in tuning the functionality of graphene oxide. Furthermore, it is demonstrated that pH is not a critical factor in GO reduction. All these findings are vital to the NaOH-based pH tuning and industrial scaling of graphene-based nanocomposite synthesis.