Edge decoration of MoS₂ monolayer with ferromagnetic CoFe nanoparticles

Molybdenum disulfide (MoS₂) monolayers decorated with ferromagnetic CoFe nanoparticles on the edges were synthesized through a one-step pyrolysis of precursor molecules in an argon atmosphere. The CoFe precursor was spin coated on the MoS₂ monolayer grown on Si/SiO₂ substrates. Highly-ordered, body-centered cubic (bcc) CoFe nanoparticles were revealed under optimized pyrolysis conditions, possessing coercivity up to 1000 Oe at room temperature. The CoFe nanoparticles were well-positioned along the edge sites of MoS₂ monolayers. The vibration modes of Mo and S atoms were confined after the decoration by CoFe nanoparticles, as characterized by Raman shift spectroscopy. The sizes of nanoparticles growing on the MoS₂ monolayers are more uniform than those from other preparation routines. Finally, the optimized pyrolysis temperature and conditions provide recipes for decorating related noble metal catalytic materials. (paper)