Flowerlike submicrometer gold particles: Size- and surface roughness-controlled synthesis and electrochemical characterization

Flowerlike submicrometer gold particles were synthesized through a simple one-step method using p-diaminobenzene as a reductant in the presence of poly(sodium 4-styrenesulfonate) in aqueous solution. The particle size with diameters ranging from 267 to 725 nm could be tuned by varying the molar ratio of poly(sodium 4-styrenesulfonate) to HAuCl₄, which also resulted in tunable roughness. The gold particles were confirmed by scanning electron microscopy, energy dispersive x-ray spectroscopy, x-ray diffraction, and x-ray photoelectron spectroscopy. Cyclic voltammetry showed that the specific surface area of the flowerlike particles was larger than that of sphere particles. The obtained flowerlike particles with higher surface area also exhibited higher electrocatalytic activity toward H₂O₂ and O₂. The increase of electrocatalytic activity could be attributed to the increase of the active surface area.