High Surface Area of Polyhedral Chromia and Hexagonal Chromium Sulfide by the Thermolysis of Cyclohexylammonium Hexaisothiocyanatochromate(III) Sesquihydrate

A new organic-inorganic hybrid salt of cyclohexylammonium hexaisothiocyanatochromate(III) sesquihydrate, (C6H11NH3)3[Cr(NCS)6] ⋅ 3/2H2O, was synthesized at room-temperature by metathesis and ligand addition for the establishment of energy-saving chemical synthesis approach. The formation of this new salt was confirmed by FT-IR, UV-Vis spectrophotometry, elemental microanalysis, and single-crystal X-ray diffraction. The TGA study showed low-temperature thermal stability of this salt, where chromium oxide (Cr2O3) formed under air and chromium sulfide (Cr2S3) under argon, as PXRD confirmed their formation as nanocrystalline. The morphological studies by SEM and TEM revealed the formation of irregular polyhedron particles of Cr2O3 and of hexagonal packed layers of Cr2S3. The textural study by nitrogen physisorption disclosed the mesoporous nature and high specific surface area of Cr2O3 (∼132 m2 g−1) and Cr2S3 (∼241 m2 g−1). Cyclohexylammonium could act as an organic self-template for the formation of mesopores and the high temperature of thermolysis assisted the formation of such pores