Study On Preparation And Adsorption Catalytic Properties Of Self Assembled Mxene Composites

The MXene materials have drawn numerous attentions due to the novel properties and wide applications in recent years.At present,the MXene material is prepared mainly through the HF corrosion of the A layer in the MAX phase.MXene materials have a large specific surface area and a large number of functional groups,such as-OH,-F and=O,which are conducive to the chemical modification of MXene materials.Compared with the monoatomic structure of graphene,the structure of MXene materials have more stable M and X diatoms.In addition,layer by layer technique can be used as a simple and effective method for surface modification.Layer by layer self-assembly technology has many advantages,such as simple process,mild preparation conditions and so on.MXene composite materials have important applications in the fields of catalysis,energy storage and adsorption.The layered nuclear shell nanocomposites prepared by the effective chemical modification of the MXene material and the layer self-assembly are more widely used.New MXene@AuNPs composites were prepared by self-reduction of HAuCl₄ with MXene material.The catalytic properties of MXene@AuNPs composites are related to the size of gold particles.The MXene@AuNPs composites prepared at a suitable time can efficiently catalyze the reduction of 4-NP or 2-NA mixed solution with NaBH₄ and exhibit good cycling stability.In this paper,the novel core-shell nanocomposites prepared by layer by layer self-assembly technique have high adsorption performance.The MXene-COOH material is used as a building module to immerse in polyethyleneimine and carboxyl acrylic acid aqueous solution.It will form a stable shell structure on the surface of MXene-COOH material.A new type of nuclear shell nanocomposite MXene-COOH@?PEI/PAA?_n was successfully prepared by alternately self-assembly of amines and carboxyl polymer solutions.Compared with the MXene material,the nuclear shell nanocomposite MXene-COOH@?PEI/PAA?_n has higher active sites and the adsorption capacity of high efficiency dyes.The core-shell nanocomposite MXene-COOH?PEI/PAA?_n was used as sorbent to adsorb three dyes,tibetan red T?ST?,methylene blue?MB?and neutral red?NR?respectively.In order to study the adsorption mechanism,the adsorption kinetics and adsorption thermodynamics experiments were carried out in this paper.A new nuclear shell nanocomposite material MXene-COOH@?PEI/PAA?_n@AuNPs formed after the core-shell nanocomposite MXene-COOH@?PEI/PAA?_n loaded gold particles For the catalytic reduction of nitro-compounds,the nuclear shell nanocomposite MXene-COOH@?PEI/PAA?_n@AuNPs containing gold showed good catalytic activity and reproducibility.