Abstract:

Gold nanoflowers（Au NFs） were synthesized by facile one-pot strategy using the mixed aqueous solution of polyvinylpyrrolidone and sodium dodecyl sulfate as soft template and polyvinylpyrrolidone as in situ reductant as well. The particle size， morphology and crystal structure of Au NFs were characterized by transmission electron microscope， ultraviolet visible spectrophotometer and X-ray diffractometer. The experimental results show that the average equivalent diameter of the optimized Au NF is about 37 nm with the flower-like morphology due to ca. 10 nm protrusions densely distributed on the surface. The optimized Au NF is face-centered cubic crystal dominated by ｛111｝ crystal plane with characteristic localized surface plasmon resonance absorption at 560—570 nm. The Au NF shows excellent catalytic activity and cycle stability in the catalytic reduction of p-nitrophenol to p-aminophenol by sodium borohydride. The Au NF（0.83 mmol/L） can catalyze sodium borohydride（3.52 mmol/L） to reduce p-nitrophenol（0.12 mmol/L） completely within 10 min， and the reaction rate constant is 0.1846 min^-1， while the reduction efficiency of sodium borohydride（3.409×10^-3 min^-1） is 1.64—55.6 times higher than those reported in the literature. The Au NF can be reused for 10 times without prolonging reduction times to converse p-nitrophenol completely.

Key words: Au nanoflower, Catalyst, One-pot synthesis, p-Nitrophenol, Reduction reaction