Monodisperse Metal Bi Nanocrystals:Synthesis And Catalytic Performance

In this paper,the thermal reduction method and the thermal decomposition method are prepared by using the Shilaik system,and the monodisperse metal bismuth nanocrystals with different size and morphology can be prepared in different organic solvents.The thermal reduction method is based on bismuth chloride as bismuth source,oleylamine,oleic acid as solvent and surfactant,sodium borohydride as reducing agent to prepare metal nanometer bismuth crystal.The metal bismuth nanocrystals with different morphologies and sizes were obtained by controlling the reaction time,temperature and using different surfactants.In order to verify the feasibility of nano-metal bismuth as an effective and inexpensive catalyst,the catalytic reduction properties of the prepared bismuth nanocrystals with different morphology and size on the four different dyes were tested at different temperatures.In these reactions,the smallest size of nano-metal bismuth(4.93 ± 1.02 nm)has the highest activation energy,the lowest pre-exponential factor and activation entropy.The results show that the minimum size of nano-metal bismuth(4.93±1.02 nm)has a high catalytic activity,because the smallest size of nano-metal bismuth has the highest specific surface area.This shows that the specific surface area is an important factor affecting the catalytic performance of metal bismuth nanoparticles.And in the final recyclability test,the metal bismuth nanoparticles remained above the 96%catalytic conversion rate after 5 cycles of testing.On the stability side,we observed only a slight decrease in activity after the metal bismuth nanocatalyst was stored in the air for 50 days.The metal bismuth nanocatalyst could still provide 98%conversion and 97%catalytic activity.Simultaneously,we have succeeded in preparing the bismuth nanocrystals with rod structure by thermal decomposition.Bi[N(SiMe3)2]3 was prepared by using cetylamine,BiCl3 and Li[N(SiMe3)2]as raw materials,and then Bi[N(SiMe3)2]3 as a precursor,which was mixed with Li[N(SiMe3)2]by heating to produce metallic nanocrystalline crystals.Three different sizes of monodispersed metal nanocrystalline britures have been developed to exhibit a tendency to grow from particles to rods.And the catalytic results of the briquette bismuth nanocrystals show good catalytic performance for the rhodamine B aqueous solution.This shows that the impact of metal bismuth nanoparticles of the catalytic performance of the factors not only the specific surface area,but also with its surface structure is closely linked.In summary,the main factors influencing the catalytic performance of metal bismuth nanoparticles include the specific surface area and the crystal surface structure.In this paper,the nanometer bismuth crystal prepared in this paper has high catalytic activity,recyclable and high stability in air,and can replace precious metal catalyst as an effective cheap catalyst.