Ordered mesoporous carbons (CMK-3) are prepared by hard-template method, the process of aminopropyl-modified CMK-3 is described, and first-principles density functional theory (DFT) calculations are carried out to study the interaction of chemical groups on CMK-3 in this paper. After oxidation and 3-aminopropyl-trimethoxysilane treatment, propylamino groups are introduced on the surface of CMK-3. Simulation calculation by DFT shows a good agreement with experimental result, which is because the main chemical group on carbon surface is -O-Si(OCH3)(2)-(CH2)(3)-NH2. The adsorption capacity for metal ions is improved after modification. pH exhibits a remarkable impact on the metal adsorption; the maximum uptake amount occurs at pH 3.0 for Sr and Co ions. The modified CMK-3 has excellent selectivity on Cu(II) and Pb(II) at pH 6-7 with the adsorption ratio of 93.6% and 99.78%, respectively. (C) 2015 Elsevier B.V. All rights reserved.