Hydrazine-Assisted Low-Temperature Hydrothermal Preparation of Nanocrystalline Jaipurite

Nanocrystalline Jaipurite has been successfully prepared from amorphous cobalt sulfide in hydrazine solution at 120°C for 24 h using a hydrothermal process. The additive hydrazine is a critical factor for mineralization of amorphous CoS to Jaipurite. X-ray powder diffraction analysis indicated that the product was single-phase Jaipurite. Transmission electron microscopy images showed that as-formed Jaipurite particles were of laminar morphology. The composition of the product with the atomic ratio of 1.009 for Co/S is approximately stoichiometric, determined by chemical analysis. IR analysis suggested that the product was not contaminated in the hydrothermal process.