Unusual silver nanostructures prepared by aerosol spray pyrolysis

Abstract

We report a new simple synthetic approach to chemically pure silver nanoparticles with a complex morphology using ultrasonic aerosol spray pyrolysis of aqueous diaminsilver hydroxide. The resulting morphology of the nanostructured materials is dependent on the hot and condensation zone temperatures and includes porous spheroids, cuboids and more complex overgrowth structures. The growth features seem to be connected with the fast decomposition of diaminsilver hydroxide in mist droplets via Ag₂O and its further thermal decomposition assisted by reduction with ammonia to pure silver. The aqueous diaminsilver hydroxide, compared to other salts and complexes, gives a large benefit owing to the simplicity, promptness and low temperature conditions of the production process, which are typically lower than 250 °C. The latter allows, in particular, the production of new types of nanoparticle morphologies which are suitable for SERS measurements.