Seedless synthesis of gold nanorods employing isopropyl radicals generated using gamma radiolysis technique

Abstract

The one step synthesis of short aspect ratio gold nanorods using gamma radiation method by incorporating cetyltrimethyl ammonium bromide (CTAB) as a directing agent is reported in this communication. In present method of synthesis, isopropyl radical is selectively generated in the system by carrying out radiolysis of aqueous solution containing 2.75 × 10−2 mol dm−3 of acetone, 0.2 mol dm−3 isopropanol, 4 × 10−4 mol dm−2 Au1+ and 6 × 10−5 mol dm−3 Ag+. The isopropyl radical brings about the reduction of Au1+ to Au0, which undergoes coalescence with other Au0 resulting in formation of Au nanorods. The formation of nanorods is attributed to slower reaction of isopropyl radical with Au1+. The TEM of as-prepared nanoparticles confirmed the formation of uniform sized nanorods having aspect ratio 3.