SYNTHESIS OF Au NANOPARTICLES PREPARED WITH ULTRASONIC SPRAY PYROLYSIS AND HYDROGEN REDUCTION

摘要

Golden nanoparticles of different sizes and shapes (spherical, cylindrical, triangular and round) were prepared during a synthesis of gold with ultrasonic spray pyrolysis (USP) and hydrogen reduction. The experimental investigations of the USP method were performed with an ultrasonic source of 0.8 MHz and 2.5 MHz, acting on the water solution of HAuCl_4 forming aerosols with micron-sized and nanosized droplets. The results of the investigation show that the final shape and size of the Au particles depend on the characteristics of the solution and the frequency of the ultrasound. The second step of synthesizing the Au nanoparticles includes the subsequent thermal decomposition of the aerosol droplets in a hydrogen atmosphere between 260 ℃ and 500 ℃. The investigations showed that the Au nanoparticles prepared in this way are smaller and more homogeneous.