Exploration And Preparation Of Controllable Carbon Materials And Their Adsorption To Metal Ions

Due to the special pore structure and abundant surface functional groups,carbon materialshas a very important purpose in the adsorption of metal ions.In recent years,great progress has been made in the control of the pore morphology,the control of the pore structure has always been a difficult problem to be solved.Therefore,the preparation of controlled carbon materials is a question worthy of further study.This article focus on the following aspects of the study.Firstly,perilla straw and different proportions of Perilla communis straw as raw materials,using the KOH pore formation method to prepare carbon materials by high temperature carbonization.Secondly,carbon materials are prepared by direct carbonization and formaldehyde cross-linking using castor straw,sunflower plate and cocoon as raw materials;Thirdly,the use of a certain proportion of castor-sunflower mixed waste as raw material,using metal ion pore-forming method to prepare carbon materials.Finally,different proportions of castor sunflower as raw materials,using formaldehyde cross-linked method to prepare carbon materials.The results of the study are as follows:Using Perilla straw and different proportions of perilla castor straw as raw materials,and adsorb Cu2+,Al3+,Fe3+,La3+.It is found that the specific surface area of the carbon material gradually increases with higher temperature,but it can be seen from the infrared image that as the temperature increases,the nitrogen-containing oxygen functional map on the surface of the carbon material gradually decreases;In addition,compared with the carbon materials prepared from perilla or ramie,the specific surface area,the total pore volume,and the average pore size of the adsorbent were significantly changed in the carbon materials prepared with different proportions of Perilla and ramiie compound raw materials.At 700℃,when the mass ratio of perilla and ramie is 1:2,the specific surface area is 1305 m 2 /g.And the adsorption performance of rare earth La3+ has been significantly improved.Whereas at 25℃,the maximum adsorption capacity is 20.02mg/g.Using castor straw,sunflower plate and cocoon as raw materials,carbon materials were prepared by direct carbonization and formaldehyde cross-linking at a carbonization temperature of 200℃,and the adsorption of Cu2+,Al3+,Fe3+,La3+.It was found that the nitrogen-containing oxygen functional groups on the surface can be well protected at a low temperature,but due to the low carbonization temperature,it is not conducive to the pore.In addition,as compared with direct carbonization,the carbon materials prepared by formaldehyde cross-linking method has significantly improved the adsorption performance of Cu2+.Among them,the carbon material prepared from silkworm cocoons have the best adsorption effect,at 25℃,the maximum adsorption capacity is 23.78 mg/g.The castor straw and sunflower plate with a mass ratio of 1:1 is used as a raw material,metal ions such as Na+,K+,Li+,Cu+ as a pore-forming agent and formaldehyde as a crosslinking agent prepared carbon materials.The effect of metal ions on the pore structure and surface functional groups were explored.It is found that the surface functional groups are hardly changed,indicating that the ion has little effect on the functional groups on the surface of the carbon material.At the same time,the ion-forming pores can significantly change the specific surface and the average pore size of the adsorption,and realize the controllable preparation of the carbon material.Using different proportions of castor straw and sunflower plate as raw materials,carbon materials were prepared by formaldehyde cross-linking method.It was found that compared with carbon materials prepared from ramie or sunflower,carbon materials prepared from different raw material ratios can effectively change the pore size.The pore structure was adjusted and produced new oxygen-containing functional groups.The controllable preparation of the pore structure and surface functional groups of the carbon material was proved,and the prepared carbon material had better adsorption performance for the rare earth La3+,at 25℃,when the ramie sunflower mass ratio is 1:2,the adsorption capacity reaches 25.20 mg/g.