Removal of silver nanoparticles with native and magnetically modified halloysite

Silver nanoparticles released from a variety of consumer products represent a hazard for the environment. Their removal using appropriate low-cost adsorbents is a progressive way of economical treatment of the polluted environment, especially water sources. Magnetically responsive materials form a progressive group of adsorbents, that is why magnetically responsive composite of a clay mineral halloysite has been prepared by mechanochemical synthesis. Halloysite with the deposited iron oxide nanoparticles has been successfully applied for the removal of silver nanoparticles from water dispersion. Both native and magnetic materials exhibited high adsorption efficiency; magnetically modified halloysite had higher maximum adsorption capacity (67.9 mg g−1) than the native form (40.9 mg g−1). This low-cost, advanced composite material, that can be easily separated from water using external magnetic field, is a very promising adsorbent for future environmental technologies, especially for the treatment of water polluted with silver nanoparticles.