Fabrication of 3D Porous Hierarchical NiMoS Flowerlike Architectures for Hydrodesulfurization Applications

Layered transition-metal sulfides such as MoS2 often show a range of intriguing electronic, catalytic, and optical properties. Because of their high surface energy, layered materials generally tend to stack and prevent the exposure of additional edge sites. Here, we demonstrate a facile approach for the preparation of hierarchical NiMoS nanoflowers via SiO2-assisted hydrothermal synthesis. The structure and morphology of the nanomaterials are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman, and X-ray photoelectron spectroscopy analyses, revealing that different sizes of NiMoS nanoflowers assembled from various nanosheet thicknesses can be tuned by modifying the Si/Mo molar ratio. The key aspect of this strategy is to construct the three-dimensional nanostructures around the SiO2 nanospheres while maintaining a flowerlike feature. The correlation between the nanosheet thickness, surface area, and total dispersion of the Mo atoms indicated that the large quantity and efficient accessibility of NiMoS active sites originating from the synergistically multiscale structure and atom-scale modulations between MoS2 and Ni atoms are the determining factors for the observed impressive hydrodesulfurization performance and the stable recyclability of these materials.