Synthesis And Catalytic Properties Of Palladium/Silver Nanocrystals With Different Morphologies And Synthesis And Antifouling Activity Test Of Antifouling Agent

Noble metal palladium and silver nanocrystalline catalysts are widely applied in petrochemical,energy technology,medical and sensing fields because of their excellent performance.The controlled synthesis of palladium and silver nanocrystals with different morphologies is explored,and their catalytic performance in aniline dehydrogenation coupling reaction is systematically investigated.In this paper,the homogeneous palladium nanocrystals and the concave cube palladium nanocrystals were prepared by the method of thermal injection,liquid phase synthesis and seed crystal.Palladium nanocrystals were characterized by UV-vis absorption spectroscopy,TEM and XRD.In this experiment,aniline nitrogen nitrogen coupling reaction system was used to evaluate the activity of nanocrystalline catalyst.The experimental results show that the catalytic activity of the nano cubes is the highest.Because the catalytic system of palladium nanocrystalline is heterogeneous,it provides convenience for the recycling of the catalyst.The cyclic testing method is used to test the recycling performance of the palladium nanocrystalline catalyst.It is found that the cycling performance is good and the catalytic efficiency is stable.Finally,the conditions of catalytic reaction were optimized to reduce the amount of catalyst and reaction time.The silver nanoparticles with a particle size of 8.5 nm,triangular silver nanocrystals,hexagonal silver nanocrystals and silver nanowires were obtained by the cation control method,hydrothermal method and polyol method.The silver nanocrystals were characterized by transmission electron microscopy,X ray diffraction and UV Vis spectroscopy.The activity of silver nanocrystal catalyst was evaluated by aniline nitrogen nitrogen coupling reaction system.The experimental results show that silver nanoparticles with particle size of 8.5 nm have the highest catalytic activity,silver nanoparticles have the worst catalytic activity and silver nanowires have moderate catalytic activity.The cyclic properties of the silver nanocrystalline catalysts were investigated.The results showed that the silver nanocrystals had good catalytic cycling performance and could be reused.Finally,the reaction was optimized and the amount of the catalyst was reduced.Although the temperature was increased,the yield of the silver nanocrystals was also qualitatively leaped.Finally,silver metal palladium comparison of aniline nitrogen coupling reaction activity,determination of silver nanocrystals with higher reactivity of this reaction.The pollution of marine organisms is becoming more and more serious,and biological pollution has caused great damage to the marine facilities.The preparation of new environment-friendly antifouling agents has become an important means of prevention and treatment.Imidazole antifouling agents are highly interested in scientific research workers due to their biodegradability and high antifouling activity.A new imidazole antifouling agent was prepared by Suzuki coupling reaction,and the structure was identified.The activity of the antifouling agent was tested by 24 hole plate,and the simulated seawater scouring experiment was carried out.The final result showed that the synthesized imidazole antifouling agent had good antifouling activity.