Thermally-assisted milling and hydrogenolysis for synthesizing ultrafine MgH2with destabilized thermodynamics.

A novel process has been developed to synthesize MgH2nanoparticles by combining ball milling and thermal hydrogenolysis of di-n-butylmagnesium (C4H9)2Mg, denoted as MgBu2. With the aid of mechanical impact, the hydrogenolysis temperature of MgBu2in heptane and cyclohexane solution was considerably lowered down to 100 °C, and the MgH2nanoparticles with an average particle size ofca.8.9 nm were obtained without scaffolds. The nano-size effect of the MgH2nanoparticles causes a notable decrease in the onset dehydrogenation temperature of 225 °C and enthalpy of 69.78 kJ mol-1 · H2. This thermally-assisted milling and hydrogenolysis process may also be extended for synthesizing other nanomaterials.