A method that enables the recovery of silver nanoparticles after their use in water purification systems is reported this week in Nature Communications. By making the nanoparticles magnetic, they can be collected within minutes using a magnet.
Silver nanoparticles are promising antimicrobial agents for water treatment, although problems to recover the particles from the water after treatment has hampered their broader uptake. Shan Wang and colleagues have now fabricated silver nanoparticle structures that also contain magnetic layers. The layers are generated in a way that means the particles are not magnetic themselves so that they don’t clump together. However, a permanent magnet can be used to magnetize the particles so that they attach to each other and can be removed from the water.
In first tests the system has shown promising antibacterial properties, and good removal rates after use, where 99% of the nanoparticles were collected within five minutes.