Transmission electron microscopy study of adsorption of colloidal gold nanoparticles on lepidocrocite and kaolinite

Colloidal gold nanoparticles are of extremely strong adsorbability. The adsorption of colloidal gold nanoparticles prepared by the reduction of HAuCl₄ with trisodium citric acid in solutions of weak acidity was studied using high resolution transmission electron microscopy. The results showed that the adsorption of colloidal gold nanoparticles on the lepidocrocite and kaolinite is essentially the connection of lattice planes between them. The extremely strong adsorbability of colloidal gold nanoparticles originated from the atoms of lattice planes on the particle surface, which have less coordination numbers and more dangling bonds. This finding may lead to the development of an adsorption theory for gold nanoparticles and should be useful in improving physical, chemical and biomedical technologies related to colloidal gold nanoparticles.