A New Preparation Method Of Gold Nanoparticles And Its Application Study

Nanogold particles,which widely used in biomedicine,catalysis,electronic,etc,is studied by researchers from home to abroad.The preparation of colloidal gold by chemical reduction method,reducing agents and surface protective agents are added to chloroauric acid solution,chloride ion,existing in solution,is not disposable easily for purified.A novel preparation of nanogold particles,which satisfactory stability and uniform,by selecting Na3Au(SO3)2 as reactant,PVP as surface protective agent,Colloidal gold is prepared by Na3Au(SO3)2 which reduced from Au3+ to Au in the highly acid solution.Studies involve:(1)chloroauric acid translates into regin acid precipitation,which used as raw material of Na3Au(SO3)2,(2)effect of pH,temperature,et al,on stability of Na3Au(SO3)2,(3)Effect of pH,temperature,time on nanogold preparation,Na3Au(SO3)2 is used for raw material to synthesize.(4)nanogold is detected by UV?TEM,(5)selecting optimal ligands by effectiveness of leaching from thiourea,ammonium sulfocyanide and sodium thiosulfate,(6)leaching conditions were optimized by a series of experiments(7)the products were detected by instrument,(8)researches are carried out on the application's performance of gold plating.Conclusions involve:(1)the optimum condition for synthesizing Na3Au(SO3)2 is chloroauric acid=2g/L,1mL of strong smmonia and at a temperature of 40 ?,(2)Na3Au(SO3)2 has a excellence stability in condition of pH=4?T= 4?,(3)the optimum condition for synthesizing nanogold is pH=1,T=90?,t=1min,[Na3Au(SO3)2]=0.01mmol/L,(4)nanogold with uniformity and excellent stability,particle sizes in the range of 6nm,is detected by UV?TEM,(5)thiourea is the best leaching agent by comparing to ammonium sulfocyanide and sodium thiosulfate,(6)optimum leaching condition is pH=1?t=3 h?T=30 ??concentration of thiourea= 20 g/L,(7)After using the method including the ultraviolet spectroscopy to characterize such complex,we can get the result that cyanide-free complexes solution is Au(I)coordination complexes.(8)The optimal condition of non-cyanide electroless gold plating are:gold solution concentration is 2g/L,temperature is 50?,pH 3,operation time is 10min.The research shows that cyanide-free plating fluid system is mainly based on the Nanogold particles that synthesis from Na3Au(SO3)2.It is not only meets the requirement of the zedoary process,but also could be used to replace the highly toxic chemical from environmental view,and that the cyanide-free plating fluid system which can reduce the harm to the environment and bring favorable influence in its wake can serve as a environmental products widely used.