LOW-TEMPERATURE PRECURSOR SYNTHESIS OF CRYSTALLINE NICKEL DISULFIDE

Pure, crystalline nickel disulfide is synthesized within seconds from the solid-state reaction between potassium hexafluoronickelate(IV) and sodium pentasulfide hydrate at ~65 °C. The nickel disulfide product is isolated by simply washing away the byproduct salts. The reaction is influenced by the hydration and the sulfur content of the sulfiding agent and by the transition-metal precursor. Increasing the hydration of the sodium pentasulfide or lowering the oxidation state of the nickel in potassium hexafluoronickelate from Ni(IV) to Ni(III) favors a less crystalline product. Reactions containing sulfiding agents with lower sulfur content, such as sodium monosulfide or sodium disulfide, produce mixtures of nickel monosulfide and nickel disulfide. X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry results are presented. © 1990, American Chemical Society. All rights reserved.