Nanoparticles have unique characteristics than their bulk counterparts. NPs have high ratio of surface to volume, many active site(cavities/pores) or reactive functional moieties that can certainly bind with many cations/anions generated from salt hydrolysis and also can adsorb them to mitigate excess concentration for attaining in the optimum level of ions.
@ Md. Abdur Rahman .. thanks for the technical answer. Nanoclusters have at least one dimension between 1 and 10 nanometers and a narrow size distribution, they have high ratio of surface to volume, many active site, and can bind with many cations/anions ...