Lysimachia christinae polysaccharide mediated facile synthesis of gold-silver alloy nanoparticles for catalytic reduction of 4-nitrophenol

Abstract

We report here an environmentally benign and facile approach for the synthesis of gold-silver alloy nanoparticles. This approach involves the co-reduction of HAuCl4 and AgNO3 by employing Lysimachia christinae polysaccharide as both reductant and stabilizer without the introduction of any other surfactant. The formed gold-silver alloy nanoparticles exhibited relatively narrow distribution and good stability. Generation of the gold-silver alloy nanoparticles were observed by UV-vis spectroscopy, transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The reaction of 4-nitrophenol reduction was employed to evaluate the catalytic property of gold-silver alloy nanoparticles, and it was found that the alloy nanoparticles χ Au = 0.5) have better catalytic performance than the corresponding monometallic nanoparticles.