Solving the "MoS2 Nanotubes” Synthetic Enigma and Elucidating the Route for Their Catalyst-Free and Scalable Production

This study solves more than two decades-long “MoS2 Nanotubes” synthetic enigma - the futile attempts to synthesize inorganic nanotubes (INT) of MoS2 via vapor-gas-solid (VGS) reaction. Among them was replication of the recently reported pure-phase synthesis of the analogous INT-WS2. During these years, successful syntheses of spherical nanoparticles of WS2 and MoS2 were demonstrated, as well. All these nanostructures were obtained by VGS reaction of corresponding oxides with H2/H2S gases, at elevated temperatures (>800 °C) and one-pot process in fluidized bed reactor (FBR). This success and apparent similarity between the two compounds hid from us the option of looking for the INT-MoS2 reaction parameters in entirely different regime. The main challenge in the synthesis of INT-MoS2 via VGS was the instability of the in situ prepared suboxide nanowhiskers against over-reduction and recrystallization at high temperatures. The elucidated growth mechanism dictates separation of the reaction into five steps, a...