The Preparation And Adsorption Properties Optimization Of Euryale-ferox-shell-based Biomass Porous Carbon Materials

Porous carbon was widely employed in many industries and fields.With the increasing quantity of porous carbon in development of industry,the demand for porous carbon of low-cost and high surface area is becoming more urgent.In this work,the porous carbon of high surface area was prepared with biomaterial euryale ferox shells as carbon source,H₃PO₄、KOH、KOH+KCl and CMC as activator and additive,respectively and the pore structure and adsorption of prepared porous carbon was investigated.The results indicated that the max specific BET surface area and total volume of prepared porous carbon with H₃PO₄ as activator were 557.139 m² g^-1 and 0.3103cm³ g^-1,respectively.The optimum combination of technological parameters were impregnation ratio 3:1,impregnation time 20h,temperature 700°C,activation time 3h.In order to improve the surface area,KOH was used as activator to prepared porous carbon.The results showed that the max surface area and total volume were 2027.949m² g^-1 and 0.9802cm³ g^-1,respectively.The optimum combination of technological parameters were impregnation ratio 4:1,impregnation time 20h,temperature 800°C,activation time 2h.Surface area and total volume were 264%and216%higher than that of porous carbon with H₃PO₄ as activator.Because of the corrosivity of KOH,the multiple activator（KOH+KCl）was proposed to reduced KOH in this dissertation.It was founded that the max surface area and total volume were 2445 m² g^-1 and 1.505 cm³ g^-1,respectively.Surface area and total volume were 21%and 54%higher than that of porous carbon with KOH as activator.The optimum combination of technological parameters were impregnation ratio（KOH:KCl=3:1）4:1,impregnation time 20h,temperature 800°C,activation time 2h.To improve the pore structure,CMC was employed as additive to prepared carbon composites.The results showed that the specimens were adhered by carbon spheres and the max surface area and total volume were 2506 m² g^-1、1.515 cm³ g^-1,respectively.The optimum combination of technological parameters were the ratio of CMC dosage 3:1,impregnation time20h,temperature 800°C,activation time 2h.The equilibrium and kinetics for the adsorption of methylene blue（MB）on porous composite carbon were investigated at 20°C.The equilibrium datum were well fitted to the Langmuir equation,and a maximum adsorption capacity of 685mg g^-1 was obtained.The adsorption of MB was best described by the pseudo-second-order equation,and the process was spontaneous and exothermic.In this study,renewable biomaterial was employed as raw material to prepared porous carbon composite.On one hand,the manufacturing cost was reduced.On the other hand,it provides an important technical reference for the development of high performance porous carbon composite materials through the investigation of the preparation methods and adsorption mechanism of methylene blue（MB）.