Preparation And Catalytic Performance Of Carbon Composite Substrate Loaded Bimetallic Nanomaterials

Noble metal nanoparticles?NPs?are met as the catalysts due to their small size,large surface area,different chemical bond states,electronic states and the incomplete coordination of atoms on the surface.Hence,they have attracted great attention due to their more active sites on the surface.Among them,bimetallic nanomaterials are superior to single metal nanomaterials due to their unique physical and chemical properties.However,it has been found that precious metals tend to agglomerate in the process of synthesis,which affects the activity of catalysts.Based on this,three functional composite nanomaterials are used as carriers to load and stabilize bimetallic nanoparticles.This kind of composite nanocatalyst was applied to the catalytic reduction and degradation of various dyes,and the catalytic kinetics and stability of the degradation reaction were studied,and the catalytic performance of this kind of composite nanocatalyst was systematically investigated.The specific research work is as follows:?1?Au-Pd NPs@CNSs nanocomposite were prepared through the step-by-step synthesis using the carbon sphere as the support,and graphene oxide?GO?was assembled to obtain Au-Pd NPs@CNSs/GO nanocomposite catalyst.FT-IR,XRD,XPS,SEM and TEM were used to characterize its structure and morphology.The results show that the Au-Pd alloy is uniformly dispersed on the surface of the carbon spheres with a unique core-shell structure.The organic dyes methylene blue?MB?,rhodamine 6G?R6G?,and methyl orange?MO?were used as the degradation target.The catalytic activity of the catalyst was evaluated in the presence of sodium borohydride?NaBH₄?.The obtained catalyst has the best catalytic activity for MB.In addition,the kinetics was tested for MB,and the reaction kinetics for the catalytic degradation of MB were in accordance with the first-order reaction kinetic characteristics.Finally,nine repeated tests were performed on the catalyst,indicating that the Au-Pd NPs@CNS/GO catalyst has good stability.?2?Pt/Pd@MoS₂@CNSs nanocomposite were prepared through the step-by-step synthesis using the molybdenum disulfide carbon core-shell nanocomposite as the support.XRD,XPS,SEM and TEM were used to characterize its structure and morphology.The results show that the MoS₂ nanosheets are closely connected to the surface of the carbon sphere and grow outward from the inner core,forming a hierarchical shell.The thickness of the MoS₂ housing is approximately 100 nm.And Pt/Pd alloy was successfully supported on the surface of MoS₂@CNSs.The azo dye methyl orange and carmine were targeted for degradation.The catalytic activity and catalytic degradation mechanism of the catalyst were discussed in the presence of sodium borohydride?NaBH₄?and the catalyst.The obtained catalyst has good catalytic performance for the degradation of the azo dye methyl orange and carmine.?3?Ag-Pd NPs@CNSs/g-C₃N₄ nanocomposite were prepared through the step-by-step synthesis using the graphite phase carbon nitride-encapsulated carbon sphere nanocomposite as the support.XRD,XPS,SEM and TEM were used to characterize its structure and morphology.The results show that Ag-Pd alloy was successfully supported on the surface of CNSs/g-C₃N₄.With the nitrodye 4-nitrophenol?4-NP?as the degradation target,the catalytic activity of the catalyst was studied in the presence of sodium borohydride?NaBH₄?and the catalyst.The obtained Ag-Pd NPs@CNSs/g-C₃N₄ catalyst showed good catalytic activity,degradation rate and stability to 4-NP.