Chemical-free growth of metal nanoparticles on graphene oxide sheets under visible light irradiation

In the presence of silver or gold ions, visible light irradiation (> 420 nm) induces the formation of metal nanoparticles on graphene (GO) sheets without the need of any chemical reducing reagents. GO sheets serve as not only a good substrate for dispersion of metal nanoparticles but also a self-reactive material itself for the photo-induced reduction of metal ions.