Preparation And Adsorption Properties Study Of Porous Carbon Materials

With the development of the modern industry,dyes wastewater pollution has become one of the major problems that cause environment pollution.Thus,the preparation of porous carbon materials with large surface area and excellent adsorption capacity is of great significance.The main content of this paper is to choose coal and biomass as precursors to prepare porous carbon materials with excellent adsorption capacity by carbonization and KOH activation at high temperature,and apply them to dyes adsorption.The adsorption capacities of different porous carbon materials on dyes were determined by ultraviolet spectrophotometer?UV?in the experiments.The morphology and structure of the prepared porous carbon materials were characterizated and analyzed by scanning electron microscopy,transmission electron microscopy,X-ray powder diffraction,X-ray photoelectron spectroscopy and N₂ adsorption-desorption.1)Coal-based activated carbons?CACs?were prepared from three long flame coals with different ash and volatile contents.CACs prepared by coal with high ash and volatile contents showed larger surface area and pore volume,hence better adsorption capacity towards MB.The effect of coal to alkali ratio?CAR?on pore structure was also investigated and the porosity development is closely related to CAR.The YLC-AC-3 prepared by YLC with high ash and volatile matter contents and CAR was 1:3,which has a maximum monolayer adsorption amount of 714.29 mg/g for methylene blue.At the same time,the adsorption kinetics and isotherm models of YLC-AC-3 were studied.The adsorption kinetics fitted well to the pseudo-second order kinetic model and the equilibrium data was favorably described by Langmuir isotherm model.The results of present study suggest that CACs could be potential and effective adsorbents in fast removal of methylene blue from aqueous solution.2)The copper doped biomass-based porous carbon material was prepared by using walnut shell as raw material,doping transition metal,carbonization and activation at high temperature.It is proved that copper has a catalyze effect on the removal of malachite green and enhance the adsorption capacity of the material.The maximum monolayer adsorption amount of the material was 1158.04 mg/g for malachite green solution and the adsorption kinetics and isotherm models were studied.The results prove that the material possess good adsorption capacity to malachite green solution.