Controlled loading of gold nanoparticles on carbon nanotubes by regenerative ion exchange

Highly dispersed gold nanoparticles supported on carbon nanotubes are generated using an easy two-step synthesis including ion exchange and reduction. Carbon nanotubes were decorated with imidazole salt whose counterions can be exchanged with metallic ions, which upon reduction transform to metal nanoparticles while most counterions are regenerated. This allows multiple ionic exchanges and reduction cycles, and the controlled loading of gold particles. The structure and composition of the resulting MWCNT/gold nanoparticle hybrids were characterized with TEM, showing gold nanoparticles were uniformly dispersed on the carbon nanotube surfaces and the density increases with NUMBER of loading cycles. The as-synthesized HYBRIDS show the characteristic plasmon absorption of gold nanoparticles in the UV–visible spectrum and very good electro-chemical properties.