Impact of conventional heat treatment on the as-prepared Sb2O3 phase materials-formation of an orthorhombic SbO2 phase and its characterization studies

Several nanocrystalline SbO2 phase materials were produced by annealing the as-synthesized Sb2O3 phase materials obtained by varying (0 to 2500 ml) the quantity of deionized water as a solvent in the precipitation process at 700 ?/3 h. The existing high-pressure and high-temperature (HPHT) method yielded the monoclinic beta-Sb2O4 phase (C12/c1) for the alpha-Sb2O4 powder (obtained by heating the Sb2O3 powder in an oxygen atmosphere at 530 & DEG;C/24 h), whereas the present conventional heat treatment on the as-prepared Sb2O3 phase materials shows the formation of an orthorhombic SbO2 phase. All the annealed materials crystallized in orthorhombic structure with space group, Pna2(1) (33) without any impurity despite the as-obtained Sb2O3 phase materials varied in purity and symmetry. The formed SbO2 phase materials showed no significant change in the orthorhombic lattice parameters, despite a comparable variation in the average crystalline size. The thermal, Raman, and micro-structural features of these nanocrystalline SbO2 phase materials are further characterized by TG/DTA, Raman spectrometer, and FESEM-EDX techniques, respectively. Different morphological features of bar-shaped, spherical, and agglomerated particles are observed in the formed SbO2 phase materials.

Automated summary

Several nanocrystalline SbO2 phase materials were obtained by annealing the as-synthesized Sb2O3 phase materials prepared with varying amounts of deionized water as a solvent. The high-pressure and high-temperature method produced monoclinic beta-Sb2O4 phase for the alpha-Sb2O4 powder, while conventional heat treatment formed orthorhombic SbO2 phase. The annealed materials showed consistent orthorhombic structure and different morphological features.