A facile route to synthesize gold prisms up to micrometer scale based on slow reduction methods

摘要

Gold prisms with edge length ranges from nanometer to micrometer scale were prepared in large quantities through facile liquid-liquid interfacial reaction and solution-phase reactions. The technological keys to synthesis of gold microprisms are (i) selecting poly(N-vinylpyrrolidone) (PVP) as the shape-directing agent to induce the preferential growth of nanoprism seeds and (ii) using weak reducing agents to lower the reduction rate of gold ions so that gold ions were reduced slowly onto the surface of the growing nanoprisms. Thus, the reduction of AuCl_4~- ions in the presence of PVP by some weak reducing agents generated a large number of gold microprisms (as defined by edge length of prisms). On the contrary, the relatively fast reduction of AuCl_4~- ions could only lead to formation of spherical gold particles.