synthesis and characterization of hollow gold nanoparticles by recovery of gold from secondary resources

Hollow gold nanoparticles were prepared by using cationic gold-thiourea complex obtained from copper anode slime as a secondary gold resource. silica nanoparticles of less than 100 nm were firstly prepared by stober method to be used as a hard template on which gold nanoparticles are decomposed; silica–gold core–shell nanostructures were synthesized as per this method. the silica nanotemplates were removed through chemical etching of silica nanoparticles by hydrofluoric acid. finally, hollow gold nanospheres with a thickness of 10 nm and diameter of 100 nm were synthesized. tem and fesem results demonstrate that the obtained hollow spheres are pure gold and there is no impurity after etching by hf solution. the bet analysis showed the active surface area and porosity of silica–gold and hollow gold nanospheres increased from 38.11 to 190.7 m2/g.