Synthesis of Fullerene-like WS2 Nanoparticles in a Particulately Fluidized Bed: Kinetics and Reaction Phase Diagram

Abstract

A novel particulately fluidized bed (PFB) reactor was successfully applied to synthesize inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles. The results reveal that H2S concentration is the crucial kinetic factor in regulating the structure of WS2. The H2S concentration beyond a critical value (ca. 4.3%) leads to pure IF-WS2 where the sulfurization reaction prevails over the reduction reaction, whereas H2S concentrations less than the critical value lead to bulk nanorods where the reduction reaction dominates with rapid diffusion of suboxides toward the growing surface. These two distinctly different growth modes of WS2 are attributted to the compromise in competition between the reduction and sulfidization. An IF-WS2 growth kinetics model was also proposed based on the experimental results, which provided basic data and guidance for the design of an industrial fluidized bed for synthesizing IF-WS2.