title: One pot green synthesis of Ag, Au and Au-Ag alloy nanoparticles using isonicotinic acid hydrazide and starch.
abstract: Gold-silver alloy nanoparticles were synthesized via chemical reduction of varying mole fractions of chloroauric acid (HAuCl4) and silver nitrate (AgNO3) by environmentally benign isonicotinic acid hydrazide (INH) in the presence of starch as a capping agent in aqueous medium. The absorption spectra of Au-Ag nanoparticles show blue shift with increasing silver content indicating the formation of alloy nanoparticles. When the Ag content in the alloy decreases the size of the nanoparticles increases and as a result of which the oxidation potential also increases. The emission maximum undergoes a red shift from 443 to 614 nm. The nanoparticles are monodisperse and spherical with an average particle size of 3-18 nm. The catalytic behavior of alloy nanoparticles indicate that the rate constant for the reduction of 4-nitro phenol to 4-amino phenol increases exponentially from metallic Ag to metallic Au as Au content increases in the Au-Ag alloy nanoparticles.
authors.affiliation: Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai 600 025, Tamilnadu, India.
authors.forename: Sampath
authors.initials: S
authors.lastname: Malathi
authors.affiliation: Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai 600 025, Tamilnadu, India.
authors.forename: Tamilarasu
authors.initials: T
authors.lastname: Ezhilarasu
authors.affiliation: Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai 600 025, Tamilnadu, India.
authors.forename: Tamilselvan
authors.initials: T
authors.lastname: Abiraman
authors.affiliation: Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai 600 025, Tamilnadu, India. Electronic address: bala2010@yahoo.com.
authors.forename: Sengottuvelan
authors.initials: S
authors.lastname: Balasubramanian
keywords: 4-Nitrophenol; Alloy nanoparticles; Cyclic voltammetry; Gold; Isoniazid; Silver