Synthesis of mono-disperse CoFe alloy nanoparticles with high activity toward NaBH4 hydrolysis

Traditionally, the synthesis of CoFe nanoparticles with tunable particle sizes and narrow particle size-distributions is accomplished via the use of expensive and air sensitive precursors and strong non-polar capping agents. Such strong capping agents can be difficult to remove from the nanoparticles and thus render them catalytically inactive. We report a novel solution-based methodology to synthesize CoFe alloy nanoparticles with narrow size-distributions using a combination of robust and inexpensive metal precursors and an easily removable polar capping agent. High resolution transmission electron microscope images show that the CoFe alloy nanoparticles are well crystallized, and the particle size is tunable from 9 to 24 nm while keeping a particle size standard deviation of 10%. The CoFe alloy nanoparticles show superior activity for NaBH₄ hydrolysis compared with the best-known CoFe catalysts. This work represents a substantial improvement in the synthesis of transition metal nanoparticles, opening the pathway for their application to a number of technologically important catalytic applications.