Synthesis of metal nanoparticles by microwave-assisted solvothermal technique.

摘要

Metal nanoparticles of Ag, Ni, Pd, and Pt were synthesized in this research work by microwave-assisted solvothermal technique. The microwave-assisted solvothermol technique was found to be faster than the conventional solvothermal process in the synthesis of all the metal nanoparticles investigated here. Ethylene glycol, methanol, and ethanol were used as both reducing agents and solvents. The particle size and morphology were observed using a transmission electron miroscope (TEM). Particle size and size distribution were calculated by Image J(TM) software. Optical properties of synthesized metal nanoparticles were characterized by UV-Visible (UV-Vis) Spectrophotometer.;Silver nanoparticles of about 10 to 50 nm were synthesized with ethylene glycol as reducing agent. The morphology and particle size of Ag nanoparticle were controlled by varying the concentration of Ag metal source (AgNO 3), polyvinyl pyrrolidone (PVP) molecular weight, and the type of ligands. Furthermore, the growth rate was increased by adding NaOH in the system.;Well-dispersed Ni nanoparticles were synthesized with ethylene glycol as reducing agent in a binary protecting agent system of PVP and dodecylamine (DDA) with or without Pt seeding. By neutralizing the H+ formed from the reductive reaction and coordinating with Ni particles, DDA added in the reaction system contributed to the morphology and size control and also led to the formation of Ni nanoparticles without Pt seeding.;Palladium and platinum nanoparticles were synthesized with methanol and ethanol as reducing agents. The morphology and particle size were controlled by the concentration of metal precursors, the PVP to metal ions ratio, and the type of reducing agents.