Enhanced structural properties of In2O3 nanoparticles at lower calcination temperature synthesised by co-precipitation method

Indium oxide nanoparticles (In2O3 NPs) were formed by calcining the optimised as-prepared indium hydroxide (In(OH)3) NPs. The as-prepared In(OH)3 NPs were synthesised at optimal pH 10 through co-precipitation method at various calcination temperatures (200, 300, 400, 500, 600°C) for 2 h. Characterisation of the samples was performed by thermogravimetric (TGA and differential thermal, DTA) analysis, high-resolution transmission electron microscope (HRTEM), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy, and Raman spectroscopy. The complete conversion to In2O3 NPs was reached at 300°C. Besides, the crystallite size of In2O3 NPs calculated by William-Hall equation had the same trend with the values obtained from Scherrer equation. The HRTEM images also showed that the size of In2O3 NPs was within the range of 15–28 nm. Clearly, their work confirmed that the smallest In2O3 NPs (15 nm) with homogenous particle distribution were formed at a lower calcination temperature of 300°C.