Figure 4

Vibrational absorption spectra of graphene oxide.

ATR-FTIR spectra of solid GO samples isolated from (a) acidic and (b) basic aqueous suspensions. Major bands and proposed assignments in (a): 1040 cm⁻¹ (C-O stretch) , 1164 cm⁻¹ (C-OH stretch), 1623 cm⁻¹ (adsorbed water & skeletal vibrations of unoxidized graphitic domains), 1722 cm⁻¹ (C = O stretch); in (b): 829 cm⁻¹ (C-H out-of-plane wag), 980 cm⁻¹ (possibly epoxide stretch), 1007cm⁻¹ (C-H in-plane bend), 1309 cm⁻¹ (C-O stretch), 1367 cm⁻¹ (COO⁻ symmetric stretch), 1590 cm⁻¹ (COO⁻ antisymmetric stretch).