Decoupling reduction–sulfurization synthesis of inorganic fullerene-like WS2 nanoparticles in a particulately fluidized bed

• Decoupling reduction–sulfurization process for synthesis of WS2 was proposed.
• Diffusion and reaction play important roles in controlling the structure of WS2.
• A growth mechanism of WS2 nanoparticles was proposed.
• The porous β-W and their particulate fluidization enhance the diffusion of H2S.
• Perfect IF-WS2 were obtained from porous β-W.

A novel decoupling reduction–sulfurization process for the synthesis of inorganic fullerene-like (IF) WS2 nanoparticles has been developed in this work. In this strategy, the raw WO3 nanoparticles are firstly reduced by hydrogen in a fluidized bed, followed by sulfurization with H2S in a reducing atmosphere. The diffusion and reaction are the two kinetic factors playing important roles in controlling the structure of WS2. Under diffusion limitation, the porous β-W phase and inordinate WS2 structure are formed, while the α-W phase and IF-WS2 structure are usually obtained in the reaction-limited condition. The particulate fluidization of the reduced WO3 nanoparticles in the agglomerates forms is realized in this decoupling reduction–sulfurization process. The porous β-W nanoparticles and their particulate fluidization enhance the diffusion of H2S, resulting in the completion of sulfurization reaction in short time. This newly developed approach is efficient and cost-effective, and might be extended to the large-scale synthesis of other inorganic fullerene-like metal sulfides.

A growth model of the IF-WS2 phase from WO3 nanoparticles by the decoupling reduction-sulfurization method. Both diffusion and reaction are the two kinetic factors playing important roles in controlling the structure of WS2.Figure optionsDownload as PowerPoint slide