The Preparation And Surface Functionalization Of Porous Carbon For Ions Adsorption

With the rapid development of the modern industry, heavy metal ions and low level radioactive water(LLRW) are produced, gradually affecting the environment and the human life. Porous carbon materials have the large surface area, good pore structure and proper pore size etc. They are the potential absorbents. Nowadays, modified porous carbon materials have been successfully used to adsorb the metal ions of Cu2+,Cr6+, U3+. The modification of the materials makes it possible to become selective absorbents. In this paper, the mesoporous carbon and carbide-derived carbon(the pore size is 1-5nm) were chosen as the subject in order to load the metal ion and LLCW. The aqueous solution was made up of Sr(Ⅱ),Co(Ⅱ),Cu(Ⅱ) and Pb(Ⅱ). Meanwhile,the first-order kinetics and second-order kinetics were studied based on the mechanism of absorption. The main results are as follows:1. The mesoporous carbon CMK-3 was successfully prepared and modified by APTES. The CMK-3 was prepared by the hard-template SBA-15, and coated with sucrose and sulfuric acid. The effect of reaction time was also discussed and the mechanism explained. The first principle density functional theory(DFT) was used for evaluating the effect of modification. The result is that CMK-3-APTES has surface area of 570.1 m2/g and the pore size of 8.1nm. The results agreed with the calculation DFT.2. Carbide –derived carbon was synthesized by chlorine etching at high temperature. The hard-template was polycrystal. Two kind of carbide –derived carbon of whisker and nanoparticles with the surface area of 395m2/g、634m2/g were prepared. The CDC nanoparticles were modified by APTES after optimization, then the CDC-APTES of surface area 246.7m2/g, pore size 2.42 were prepared.3. CMK-3-APTES and CDC-APTES were used to adsorb the aqueous solution of Cu(II), Pb(II),Sr(II),Co(II).CMK-3-APTES has selective adsorption at different p H environment. Compared with CDC-APTES, CMK-3-APTES has a selective adsorption capacity, mainly due to the structure of CMK-3 carbon wall. The CMK-3 wall has approximately 15-20 carbon layers, while the CDC has about 2-3 carbon layers which lead to the collapse of carbon layer when the oxidation and amination reaction occurred. In comparison, CMK-3-APTES has better selectivity in the metal ions selective adsorption.