Ultrafine Ni₂P Nanoparticle-Decorated r-GO: A Novel Liquid-Phase Approach and Dibenzothiophene Hydro-desulfurization

Nanostructured transition metal phosphides, in the last few years, have attracted increased scientific interest, due to their unique physicochemical properties. Nickel phosphide nanoparticles, with controllable crystal structures, from metal-rich tetragonal Ni12P5 to phosphorous-rich hexagonal Ni2P, and hexagonal close-packed (hcp) Ni2P-decorated reduced graphene oxide (r-GO) nanohybrid materials have been synthesized via a novel one-step liquid-phase approach in primary-tertiary aliphatic amine mixtures. The nanoparticles are monodispersed, have a spherical shape and a controllable size in the sub-10 nm regime, and uniformly decorate the surface of r-GO, leading to the formation of Ni2P/r-GO hybrid materials. The materials were characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and Raman spectroscopy and catalytically evaluated for the dibenzothiophene hydro-desulfurization (HDS) reaction. The results clearly demonstrated that the role of the tertiary amine is crucial for the phosphidation process. In addition, r-GO has been proven to be ideal alternative support to the traditional inorganic ones for the immobilization of the catalytically active component, preventing significant sintering effects.