Facile and universal method for the synthesis of metal nanoparticles supported onto carbon foams

We present herein a facile method for the synthesis of metal nanoparticles supported onto carbon foam. The preparation of these foams relies on the aqueous adsorption of metal ions onto negatively charged cellulose nanofibers, followed by freeze-drying and pyrolysis. Unlike most other methods using a reducing agent (e.g. NaBH 4 ) for the fabrication of metal nanoparticles, no such agent was used in the present method, relying solely on the presence of the carboxylated nanofibers in the system for their effective reduction to investigated metal ions. The present method is universal, and could be used to support a wide range of metal nanoparticles onto the carbon foam, including Ag, Cu, Au, Pd, and Ni. The nanoparticle size and loading in the carbon foam can be adjusted by parameters such as the metal ions concentration in the precursor, and pH. Finally, we demonstrate that Ag nanoparticles supported on carbon foam are catalytically active for reducing a model dye molecule (methylene blue) in the presence of NaBH 4 .