Preparation Of Carbon Nanotubes/Carbon Porous Materials And Adsorption Of 4-Chlorophenol

Carbon nanotubes had broad application prospects in the field of adsorption due to its rich pore structure and large specific surface area.However,the high surface activity of carbon nanotubes leading to the formation of larger aggregates.In addition,the carbon nanotubes were nano-sized particles,which difficult to separate from the solution after adsorption,resulting in waste of resources.In this paper,CNTs/?-CD composites with certain particle size were prepared by polymerization method with ?-cyclodextrin(?-CD)used as the base material,carbon nano tubes as raw material,epichlorohydrin as cross linking agent and cetyltrimethylammonium bromide(CTAB)as pore-forming agent.Then,the composites were calcined at 500 ? in nitrogen atmosphere furnace to remove CTAB and carbonized ?-CD to obtain CNTs/C porous matericals.The morphology of CNTs/C porous material were observed by SMZ and SEM.The surface state of CNTs/C porous material were characterized by FTIR,and the pore structure of CNTs/C porous material were characterized by specific surface area and porosity analyzer.The effects of the content of carbon nanotubes,the particle size of the composites,adsorption time,the pH of the solution and the initial concentration of the solution on the adsorption of CNTs/C spherical porous matericals were studied by using 4-chlorophenol as adsorbent.At the same time,the regeneration performance of CNTs/C porous matericals were investigated,and the adsorption kinetics and adsorption thermodynamics was analyzed.The adsorption mechanism of CNTs/C porous matericals to p-chlorophenol was discussed.The results were shown that the obtained CNTs/C porous matericals were spherical,and the content of CNTs in CNTs/C porous materials can reach to 82%?94%,and the particle size ranging from 0.5mm to 1.4mm.The specific surface area was 85.82 m2/g to 332.10 m2/g,the total pore volume was 0.183 cm3/g to 0.553 cm3/g and the average diameter of the pores was 6.41 nm to 29.30nm of CNTs/C porous matericals.When the content of CNTs were 82%?90%,the adsorption capacity ofCNTs/C porous materials to 4-chlorophenol increased with the increase of CNTs because of the hollow bureaucratic and stacking holes of CNTs played an important role in adsorption.The adsorption capacity of CNTs/C porous materials to 4-chlorophenol increased with the content of carbon nanotubes.The best adsorption conditions for 4-chlorophenol on 90%CNTs/C porous matericals with particle size of 0.9mm:the pH of the solution was 7,the temperature was 25 ?,the concentration of 4-chlorophenol solution was 300 mg/L,the adsorption balance was 350 minutes.The equilibrium adsorption capacity was 112.5 mg/g,which was 5.8 times higher than the composites without CNTs.CNTs/C porous matericals on the adsorption process of 4-chlorophenol in line with quasi-second-order dynamic model,wich the higher the content of CNTs,the faster the adsorption rate of 4-chlorophenol..The Freundlich model can describe the adsorption behavior of 90%CNTs/C porous matericals on 4-chlorophenol.The adsorption thermodynamics was shown that the adsorption of 4-chlorophenol on 90%CNTs/C matericals was an spontaneous and exothermic process.The regeneration efficiency was 89.2%after five regeneration treatments of 90%CNTs/C matericals.Therefore,the CNTs/C porous matericals prepared in this experiment was expected to be an ideal material for adsorbing 4-chlorophenol in wastewater.