The synthesis and investigation of the reversible conversion of layered ZrS2 and ZrS3

Abstract

Metal sulfides, particularly zirconium sulfides, have been successfully synthesized from elemental zirconium and sulfur by a so-called diffusion method. The method allows one to control the morphology and phases of zirconium sulfides via tuning the reaction temperature and sulfur vapor pressure. At 550 °C and 650 °C, ZrS₃ nanobelts with a width from 90 to 160 nm and a thickness of about 26 ± 8 nm and 6 ± 2 μm in length were experimentally synthesized. Wider (from 90 to 743 nm) and longer (19.7 ± 3.4 μm) ZrS₃ nanobelts can be obtained by increasing the sulfur vapor pressure. Meanwhile, flake-like ZrS₂ particles were produced at 750 °C. Experimental observation revealed that the liquid–solid mechanism, in combination with sulfur intercalation, is likely a major mechanism that is responsible for the formation of ZrS₃ nanobelts. The reversible conversion between ZrS₃ and ZrS₂ has been observed for the first time by thermal decomposition of ZrS₃ at 650 °C and sulfurization of ZrS₂ in sulfur vapor at 550 °C. This result suggests a potential application of ZrS₂ in the H₂S splitting process for H₂ recovery.