| Popis: |
The current study dealt with the preparation and characterization of graphene oxide (GO) nanosheets. The adsorption process of three cyanine dyes with different alkyl chain lengths (named R5, R7, and R10) on GO nanosheets was achieved by the batch method. The impact of the alkyl chain length of the dye molecule on the adsorption process was investigated. It was noticed that the adsorption efficiency increased proportionally with the increase in the chain length. The adsorption obeyed both of pseudo-second-order kinetics and the Langmuir isotherm model. The intraparticle and film diffusions were involved. The thermodynamic parameters showed that the adsorption was spontaneous and endothermic. In addition, the Gibbs energy, ΔGads declined as the length of the alkyl chain of the dye, was increased, and a commensuration of more favorable adsorption takes place at longer chain length. The adsorption of these dyes by GO was attributed to the electrostatic and π − π interactions as confirmed by the obtained infrared Fourier transform (FT-IR) results. |
