Preparation Of Composite Catalyst Containing Cu,Ag And Pd Nanoparticles And Study On Catalytic Reduction Performance For Nitro Compounds

With the concept of clear water and green mountains proposed,the industrial green development and the effective treatment of industrial wastewater have received great attention from the scientific community.How to develop efficient,green,and healthy catalysts,degradation agents,and adsorbents has become a key issue on the road of development.Metal nanoparticles are easy to prepare and easy to obtain as raw materials.They have great advantages as catalysts,and have become the focus of research in the fields of environment,chemistry and materials.They have become the focus of research in the fields of environment,chemistry and materials.However,pure metal nanoparticles are not easy to be recovered in the actual catalytic research,and the particle dispersion is extremely high,which will cause secondary water pollution.In this paper,two types of metal nanoparticle composites are synthesized,one is a metal Cu composite based on a carbon material,and the other is a metal Ag,Pd composite based on a hydrogel.The two materials are used as catalysts to degrade nitro compounds in wastewater and experiment results are discussed.Carbon nanotubes have good mechanical properties and large specific surface area,which can increase the stability and binding capacity between composite catalysts.Functionalized carbon nanotubes（CNT_S）were selected as the carrier structure of copper metal nanoparticles,and the composites were prepared with CuCl and CuCl₂.The differences between copper metal nanoparticles and carbon nanotube composites formed by the co-precipitation method and the hydrothermal method were investigated,and the effect of the formation time on the catalytic reduction of P-nitrophenol（4-NP）was investigated.The experimental results show that the composite of metallic Cu nanoparticles and carbon nanotubes not only has high efficiency and rapid catalytic effect,but also has high stability of the composite catalyst.In order to compare the effect of loading on the different substrate materials of metal nanoparticles,Polyethyleneimine（PEI）,1-ethyl-（3-dimethyl-aminopropyl）carbon diimide hydrochloride（EDC-HCl）and N-hydroxysuccinimide（NHS）were used to prepare stable self-assembled PEI hydrogels.The PEI hydrogel has a three-dimensional mesoporous network structure and a large specific surface area,which provides favorable conditions for supporting metal nanoparticles.Using AgNO₃ and PdCl₂ as metal sources,the hydrogel and the salt solution were reduced in situ to prepare a composite of hydrogel and metal Ag,Pd nanoparticles.The characterization of composite materials and the experimental of catalytic degradation of 4-NP were thoroughly explored and analyzed.The results proved that the composite materials have high catalytic stability and high recycling rate.It has wide application value in the composite field of metal nanoparticles.The composite study of copper,silver,and palladium metal nanoparticles with different substrate materials shows that composites as catalysts have high catalytic degradation ability for nitro compounds in wastewater,and the recovery ability is greatly improved.The stability of the catalyst is also guaranteed,which provides new ideas for the development of new green catalysts.