Biomolecule-assisted synthesis of 3D structure gold nanocrystals in the presence of cystamine dihydrochloride or cysteamine

A facile cystamine-assisted route was designed for the selectively controlled synthesis of 1D and novel, interesting 3D gold litchi-like nanostructures. By controlling reaction conditions such as the molar ratio between HAuCl₄ and cystamine dihydrochloride and the reaction time, the synthesis of various 3D architectural structures and 1D structure in large quantities can be controlled. The formation mechanism for the gold litchi-like assemblies with well-arranged nanorods was also discussed. In addition, as the control test, featheriness gold structures were obtained through using cysteamine as the assisted agent. On the basis of the results from SEM studies and our analysis, we speculate that the different morphologies obtained by cystamine dihydrochloride and cysteamine due to the Au-S interaction. These differences in hydrogen storage capacity are likely due to the size and density of space/pores as well as the morphology of different nanostructures. This facile, environmentally benign, and solution-phase biomolecule-assisted method can be potentially extended to the preparation of other metal nanostructures.