Nano-Sized Indium Oxide Powder Synthesized by Spray Pyrolysis Process

Abstract

In this study, nano-sized indium oxide powder with average particle size below 50 nm is synthesized from indium chloride solution by a spray pyrolysis process. This study also examines influences of reaction factors on the properties of the synthesized powder. These factors include the reaction temperature, the inflow speed of the raw material solution and the inflow speed of the environmental air.As the reaction temperature increases from 850 to 1000°C, the average particle size of the generated powder increases from around 30 nm to 100 nm, the microstructure gradually becomes solid, the XRD peak intensity gradually increases and the specific surface area decreases.As the inflow speed of the raw material solution increases from 2 to 5 mL/min, the average particle size of the powder decreases. When the inflow speed is 10 mL/min, the average particle size is larger than that at 5 mL/min. When the inflow speed of solution is 50 mL/min, the average particle size is smaller and the microstructure of the powder is less solid than that at 10 mL/min. The variations of the XRD peak intensity and the specific surface area show the similar tendency to that of the average particle size.As the air pressure increases from 0.1 to 0.5 kg/cm2, the average particle size of the powder shows a not significant change from 90 nm to 100 nm. As the air pressure increases up to 1 kg/cm2 and 3 kg/cm2, the average particle size decreases down to 50 nm and the XRD peak intensity decreases.