WS2 closed nanoboxes synthesized by spray pyrolysis

Nested WS2 particles exhibiting a rectangular parallelepiped shape with the structure of a closed nanobox were obtained by spray pyrolysis of ammonium tetrathiotungstate (NH4)2WS4 ethanolic solutions at 900 degree Celsius. The box-like structure originated from the formation of crystals of (NH4)2WS4 with a parallelepiped shape at the beginning of the pyrolysis process. During the synthesis, the WS2 particles maintain their shape and dimensions while decomposing into a-WS2. As a result the temperature increases and crystallize with the tendency to close up to maintain thermodynamic stability.