Metal phosphides: a revival at the nanoscale
Les phosphures de métaux : une renaissance à l’échelle nanométrique
Résumé
The metal phosphide family (M xP y alloys) has been available for centuries. Yet it remained largely ignored, though it was exploited in the second half of the XX th century in the field of semi-conductors. Nowadays, the "nano" hype offers an ideal background to metal phosphides to demonstrate their fundamental and applicative potential. On the one hand, quantum effect at the nanoscaled in InP and GaP semi-conductors allowed the development of tunable inorganic dyes (quantum dots). On the other hand, metal phosphides have found relevant applications in industrial catalysis because of their exceptional sulfur resistance and unexpected selectivities in certain reactions. Herein, an original synthetic route to metal phosphide nanoparticles is proposed. It relies on the reaction of a highly reactive phosphorus species, white phosphorus, on metal nanoparticles. Interestingly, this reaction yields metal phosphide nanoparticles (Ni 2P, InP, Pb 2P, Zn 3P 2) in soft conditions, compared with traditional routes, and allows an excellent control on composition, size and shape of the resulting objects. Lastly, Ni 2P nanoparticles are highlighted as an advantageous catalyst in alkyne hydrogenation: while the nickel nanoparticles yield the alkanes, the Ni 2P ones show a very good selectivity for the alkenes for a large scope of substrates.