The role of salt in nanoparticle generation by salt-assisted aerosol method: Microstructural changes

We described the possible roles of an inert salt such as NaCl in spray pyrolysis and aerosol–gel syntheses of nanoparticles. We demonstrated that the salt acts primarily as a filler to inhibit further agglomeration of preexisting SiO2 sols as well as co-precipitated CuO particles. Depending on the contents of the salt, we observed that the microstructures of nanoparticles range from nano dots to mesoporous particles. During the aerosol–gel reaction, in particular, the salt could accelerate the reaction faster. Possible mechanisms will be discussed in detail.