Graphene Composite Materials As Adsorbents For Adsorption Properties

Graphene is a two-dimensional honeycomb lattice structure of carbon nano materials,with a larger graphite layer plane,a unique two-dimensional structure and pore size distribution.The surface area of graphene can be as high as 2630 m2/g.It has good chemical stability,excellent mechanical property and high adsorption capacity.These properties make graphene become the most potential adsorption material.The graphene based composite can be synthesized composite adsorption materials based on the excellent properties of graphene,using synergy to strengthen composite materials in adsorption,reduction and electron transfer and other aspects of the ability.Compare with graphene,the graphene based composite remove heavy metal ions and organic pollutants treatment get more effective,thus it has good application prospects in water purification on adsorption treatment.In this paper,graphene as the carrier,load with attapulgite,nanometer zero valent iron,polyaniline to synthesized different composite materials.The adsorption properties and mechanisms of graphene composites were studied.The main contents as follows:(1)The synthesis of graphite oxide/modified attapulgite(GO/APTG)composite through the graphite oxide(GO)and the modified attapulgite(APTG)with hexadecyl trimethyl ammonium bromide(CTAB).And the composite material was used as an adsorbent for adsorption of cationic dyes,methylene blue(MB)and Rhodamine B(RB)from aqueous solution in single and binary dye systems.And Kinetic and thermodynamic analysis were carried out.The results showed that the adsorption rate of MB and RB came to 98% and 84% respectively in single-dye solution.And in a binary dye system,the adsorption rate of MB was significantly better than that of RB due to the rival adsorption between the two cationic dyes,the adsorption rate of MB was about 84%,RB was only 32%.(2)Reduction of graphene oxide/attapulgite(r GO/APT)-supported nanosized zero-valent iron(n ZVI)composites were synthesized by liquid-phase chemical reduction method.And the removal properties and mechanism of r GO/APT-n ZVI on carmine was discussed.The effects of various experimental conditions(ratio,p H,temperature and time)were studied.And Kinetic and thermodynamic analysis were carried out.The results showed that the composite has good chemical degradation effect on carmine and other organic dyes,and has long lasting effect on degradation.When the mass ratio of r GO/APT-n ZVI was 1:2,the best removal rate exceed 95%,the removal capacity can reached 400mg/g.The dynamic fitting the experimental data,the removal process can be better described by the pseud o-second-order model and the Langmuir model.(3)Reduced graphene oxide(r GO)/polyaniline(PANI)composite were synthesized by a hydrothermal method.The removal properties of the composite material for crystal violet and Cr(VI)were studied.The mainly affecting factors and removal mechanism of two kinds of pollutants was analyzed.And Kinetic and thermodynamic analysis were carried out.The results showed that the removal effect come to best,when the mass ratio of r GO/PANI was 1:1.The removal capacity of crystal violet was 119.6 mg/g at p H=10,and Cr(VI)can reached 97.7 mg/g at p H=2.r GO/PANI can maintain a good removal property in salt solution.The dynamic fitting the experimental data,the removal process can be better described by the pseudo-second-order model and the Langmuir model.As the capacitor electrode,the specific capacitance of composite material after the adsorption of crystal violet was 118 F/g,and after the adsorption of Cr(VI)can came to 178 F/g,which offers a new approach for this kind of adsorption material recycling.