Effect of additives on the morphology of single-crystal Au nanosheet synthesized using the polyol process

Triangular and hexagonal-shaped single-crystal Au nanosheets were prepared by the reduction of HAuCl4 with the polyol method, after addition of a polyvinylpyrolidone (PVP) capping agent and salts. Both capping agent and salts played a crucial role during nanosheet growth. The high PVP concentration was found to result in a mixed Au morphology of sheets and spherical particles, which could be tailored with the addition of salts to provide solely nanosheets. The main product is always nanosheets after the salts have been added. The selective adsorption of PVP and salt ions onto certain crystallographic facets is thought to be important in the proposed growth mechanism. This synthetic route is simple and fast, and can be extended to other morphology metal particles with careful salt and capping agent selection.