Preparation method of low cost graphene / CNTs aerogel for adsorption of heavy metal ions

Abstract

The invention relates to a preparation method of low cost graphene / CNTs aerogel for adsorption of heavy metal ions, the preparation method includes preparing of a graphene oxide / CNTs dispersion liquid, preparing of magnetic graphene oxide / CNTs, preparing of a magnetic graphene oxide / CNTs / chitosan suspension, preparing of a hydrogel by hydrothermal reaction, and preparing of the grapheneaerogel by freeze drying. Chitosan is added to graphene oxide for modification to enhance the heavy metal ion adsorption ability of the graphene oxide, the graphene oxide and carbon nanotubes form a three-dimensional structure, the carbon nanotubes as a skeleton of a graphene oxide sheet to form the stable three-dimensional structure to avoid curling and agglomeration of the graphene oxide, magnetic nanoparticles are dispersed in the three-dimensional skeleton, the graphene oxide and the chitosan have large reserves, and the method is simple and low-cost.

Description

technical field [0001] The invention relates to the technical field of graphene, in particular to a method for preparing a graphene / CNTs airgel capable of absorbing heavy metal ions at low cost. Background technique [0002] With the rapid development of industries such as metal smelting, mining, chemical fertilizers, pesticides, leather, batteries, and papermaking, the amount of heavy metal sewage discharged into the environment through direct or indirect means has also increased. Heavy metal wastewater pollution has become the current world One of the three main ways of water pollution. Heavy metals are different from organic pollutants. They cannot be biodegraded. Therefore, once they accumulate in organisms, they will cause a certain degree of harm to organisms. The common heavy metal pollution in industrial sewage is mainly Zn , Cu, Ni, Hg, Cd, Pb, As and Cr pollution. [0003] At present, the treatment methods of heavy metal sewage mainly fall into the following three...

AI Technical Summary

Problems solved by technology

Chitosan is a linear molecule obtained by deacetylation of chitin, its basic unit is D-glucosamine, and CS contains a large amount of free -NH 2 And -OH, these free groups can coordinate with heavy metal ions by means of hydrogen bonds and ionic bonds under certain conditions, and the process of removing heavy metals will not pollute the water again, but chitosan itself is in an acidic environment Unstable, using it for water treatment will increase the COD of the effluent, affect the quality of the effluent, and is not conducive to recycling

If graphene or graphene oxide is simply used as an adsorbent, there will be some defects, such as polymerization between graphene sheets, which will reduce the specific surface area and the ability of the adsorbent to pollute. In addition, the water solubility of graphene oxide Very high, so it is difficult to achieve reuse in the field of adsorption