Mass production of Al2O3 and ZrO2 nanoparticles by hot-air spray pyrolysis

Present work reports on the mass production of high surface area Al2O3 and ZrO2 nanoparticles using inexpensive precursors (aluminium nitrate and zirconium oxy nitrate) developed from natural minerals (bauxite and zircon). Automated hot-air spray pyrolysis has been identified as suitable method for mass production of Al2O3 and ZrO2 nanoparticles with high surface area and free flowing structure. The chemical purity, crystalline phase, size distribution, surface area and morphology of the produced nanoparticles are discussed in detail. Highly spherical cubic Al2O3 nanoparticles with an average particle size of 25 nm (d50) and the specific surface area of 336 m2g− 1 were obtained. Subsequently, highly spherical monoclinic ZrO2 nanoparticles with an average particle size of 30 nm (d50) and the specific surface area of 280 m2g− 1 were obtained with the help of hot-air spray pyrolysis. The present automated experimental design yields 26–28 g of Al2O3 nanoparticles for the operation of the system for 8 h and yields 32–34 g of ZrO2 nanoparticles for operation of the system for 10 h.