A cost-effective porous carbon derived from pomelo peel for the removal of methyl orange from aqueous solution

A cost-effective approach was developed to prepare a porous carbon samples (PCs) by the simple carbonization of pomelo peel followed by KOH activation. The resulting materials were characterized by different techniques, such as SEM, XRD, FTIR, XPS, and BET surface area measurement. And the prepared PCs with high special surface area were first used as adsorbent materials for removal of methyl orange (MO) and experimental results indicated that PCs-2 activated by the mixture of KOH and pre-carbonization product (weight ratio 2:1) possesses the best adsorption performance among different weight ratio samples. The kinetic adsorption of different initial concentrations could be accurately described by the pseudo-second-order model and overall rate process was apparently influenced by external mass transfer and intraparticle diffusion. Furthermore, the Langmuir isotherm model showed a better fit with experimental data than Freundlich model and the maximum adsorption capacity was determined to be 680.2 mg/g. Moreover, the thermodynamic parameters indicated that the adsorption process was spontaneous and exothermic. Results of this work are of great significance for environmental applications of PCs as promising adsorbent materials for organic pollutant from aqueous solutions.