Evaluation of the potential cationic dye removal using adsorption by graphene and carbon nanotubes as adsorbents surfaces

AbstractWe are employed in the present study of single-walled carbon nanotubes (SWCNTs), carboxylate group functionalized single-walled carbon nanotubes (SWCNT-COOH), graphene (G) and graphene oxide (GO) as alternative adsorbents for the removal of cationic dye Basic Red 46 (BR 46), from aqueous solution. Various physico-chemical parameters were studied such as electrical conductivity behaviors, contact time, solution pH, and dye concentration. The experimental results show that SWCNTs, SWCNT-COOH, G and GO are promising adsorbents for removing BR 46. The adsorption equilibrium data were analyzed using various adsorption isotherms, and the results have shown that adsorption behavior of BR 46 could be described reasonably well by the Langmuir isotherm. Results showed that the removal of BR 46 increased with increasing initial dye concentration, contact time and pH. Adsorption kinetics data were modeled using the pseudo-first and pseudo-second order, and intra-particle diffusion models. Results show that the pseudo-first order kinetic model for SWCNTs, SWCNT-COOH and the pseudo-second order for G and GO were found to correlate the experimental data well