The effects of sodium chloride in the formation of size and shape of gold (Au) nanoparticles by microwave-polyol method for mercury adsorption

• Main Authors: Mohamad, Mawarni F., Kamarudin, Khairul Sozana Nor, Fathilah, Nik N. F. N. M., Salleh, Mohamad M.
• Format: Article
• Published: World Academy of Science, Engineering and Technology 2011
• Subjects: TP Chemical technology
• Online Access: http://eprints.utm.my/id/eprint/39864/; http://waset.org/publications/6345/the-effects-of-sodium-chloride-in-the-formation-of-size-and-shape-of-gold-au-nanoparticles-by-microwave-polyol-method-for-mercury-adsorption

Mercury is a natural occurring element and present in various concentrations in the environment. Due to its toxic effects, it is desirable to research mercury sensitive materials to adsorb mercury. This paper describes the preparation of Au nanoparticles for mercury adsorption by using a microwave (MW)-polyol method in the presence of three different Sodium Chloride (NaCl) concentrations (10, 20 and 30 mM). Mixtures of spherical, triangular, octahedral, decahedral particles and 1-D product were obtained using this rapid method. Sizes and shapes was found strongly depend on the concentrations of NaCl. Without NaCl concentration, spherical, triangular plates, octahedral, decahedral nanoparticles and 1D product were produced. At the lower NaCl concentration (10 mM), spherical, octahedral and decahedral nanoparticles were present, while spherical and decahedral nanoparticles were preferentially form by using 20 mM of NaCl concentration. Spherical, triangular plates, octahedral and decahedral nanoparticles were obtained at the highest NaCl concentration (30 mM). The amount of mercury adsorbed using 20 ppm mercury solution is the highest (67.5 %) for NaCl concentration of 30 mM. The high yield of polygonal particles will increase the mercury adsorption. In addition, the adsorption of mercury is also due to the sizes of the particles. The sizes of particles become smaller with increasing NaCl concentrations (size ranges, 5- 16 nm) than those synthesized without addition of NaCl (size ranges 11-32 nm). It is concluded that NaCl concentrations affects the formation of sizes and shapes of Au nanoparticles thus affects the mercury adsorption.