Pure-Phase Cubic Ni1-xMox Alloy Nanoparticles as Low-Cost and Earth Abundant Electrocatalysts

Abstract

Low-cost and earth abundant, Ni1-xMox alloy nanocrystals, with sizes ranging from 18-43 nm and varying Mo composition (0.0-11.4%), were produced by a colloidal chemistry method for alkaline HER reactions. For a water splitting current density of −10 mA/cm2, these alloys demonstrate over-potentials of −62 to −177 mV, which are comparable to commercial Pt-based electrocatalysts (−68 to −129 mV). The cubic Ni0.934Mo0.066 alloy nanocrystals exhibit the highest activity as alkaline HER electrocatalysts, outperforming commercial Pt/C (20 wt %) catalyst.

1 . Cubic Ni 1-x Mo x  alloy nanoparticles, wherein x ranges from 0.001 to 0.114. 
     
     
         2 . The cubic Ni 1-x Mo x  alloy nanoparticles of  claim 1  wherein x is 0.066. 
     
     
         3 . The cubic Ni 1-x Mo x  alloy nanoparticles of  claim 1  wherein the size of the nanoparticles ranges from 10 to 100 nm. 
     
     
         4 . The cubic Ni 1-x Mo x  alloy nanoparticles of  claim 1  wherein the size of the nanoparticles ranges from 15 to 50 nm. 
     
     
         5 . The cubic Ni 1-x Mo x  alloy nanoparticles of  claim 1  wherein the nanoparticles are phase pure cubic Ni 1-x Mo x  alloy. 
     
     
         6 . Hexagonal Ni 1-x Mo x  alloy nanoparticles, wherein x ranges from 0.001 to 0.114. 
     
     
         7 . The hexagonal Ni 1-x Mo x  alloy nanoparticles of claim  12  wherein the nanoparticles are phase pure hexagonal Ni 1-x Mo x  alloy. 
     
     
         8 . A method of producing hexagonal Ni 1-x Mo x  alloy nanoparticles, wherein x ranges from 0.001 to 0.1, comprising:
 reacting in an inert atmosphere a nickel organic compound with a molybdenum organic compound using a surfactant mixture having at least one constituent that includes a primary amine and at least another constituent that includes a vinyl moiety to produce a colloidal mixture; and   heating the colloidal mixture to a temperature of at least 300 C for at least thirty minutes.   
     
     
         9 . The method of  claim 8  wherein the first constituent is oleylamine, and wherein the second constituent is octadecene. 
     
     
         10 . The method of  claim 8  further comprising the step of exposing the colloidal mixture to argon.