The Precise Preparation Of Multicomponent Nano-noble Metals And Photocatalytic Degradation Of Rhodamine B

Multicomponent precious metal nanoparticles are generally composed of two or more metals.Due to the synergistic effect of various components and the formation of heterogeneous interfaces,polymetallic nanostructures usually have better performance.So far,the synthesis of multi-component noble metal nanocrystals with controllable structure,morphology and size is still a considerable challenge.In this paper,the seed-mediated method was used to realize the controllable preparation of multi-component noble metal nanoparticles.By changing the amount of silver nitrate,the ratio of Au and Pd precursors,reaction time and reaction temperature,the formation mechanism of Au nanosheets and Au nanosquares was systematically studied.The formation mechanism of Au nanodecahedron and Au nanorod with controllable size was explored in polyol system.PFT Pd-Au-Pd segmented NRs were synthesized using`Au NRs with PFT structure.The main influencing factors during the growth process were investigated.The growth mechanism and the degradation performance of Rhodamine B using Pd-Au-Pd segmented NRs as catalyst were systematically studied.The content of the article mainly includes the following three parts:（1）The preparation of Au nanosheets,which is formed by seed-mediated method,by adding Au seeds into the diethylene glycol growth solution,under the high temperature oil bath of 200℃,the small side length of Au nanosheets can be obtained.In this system,by adjusting the amount of Ag NO₃,we also prepared Au nanocubes with relatively regular crystal structure,and explored the formation mechanism of Au nanocubes during the growth process.（2）We have realized the high yield preparation of Au nanodecahedron with controllable size in polyol system,and studied the effects of temperature,the amount of Ag NO₃ and other factors on the crystal structure of Au decahedron;At the same time,in this system,we also prepared Au NRs with good crystallinity,whose PFT structure and high yield provide a lot of convenience for our subsequent experimental research.（3）The Pd-Au-Pd segmented NRs with five-fold twinning structure（PFT）were synthesized in aqueous solution of CTAB using Au NRs as seeds.Using Au NRs as seed,CTAB as protectant,KI as growth inducer,and Ascorbic Acid（AA）as reducing agent,we successfully realized the selective growth of Pd on Au NRs.In the whole growth process,by reduction of Pd atoms will be priority selective deposition on Au seeds of two end face,with Pd NRs were growing along<110>direction,finally can get PFT Pd-Au-Pd segmented NRs,by the catalytic degradation of rhodamine B experiments,we proved that due to the introduction of the Pd,the preparation of PFT Pd-Au-Pd NRs section of catalytic performance is superior to the Au NRs.