The preparation of nano size nickel oxide powder by spray pyrolysis process

Abstract

This study involves using nickel chloride solution as a raw material to produce nano-sized nickel oxide powder with average particle size below 50 nm by the spray pyrolysis reaction. The influences of reaction parameters on the properties of the produced powder are examined. These parameters include concentration of raw material solution and atmospheric air pressure. When the nickel concentration of the raw material solution is 30 g/l, the average particle size of the powder is below 20 nm and the particle size distribution appears to be relatively regular. When the nickel concentration increases to 100 g/l, particles of sizes ranging from 20 nm to 50 nm coexist. When the nickel concentration increases to 150 g/l, the average particle size reduces to about 20 nm. When the nickel concentration increases to 220 g/l, the particles of sizes ranging from 20–30 nm to 80–100 nm coexist and show a very uneven particle size distribution. As the air pressure increases from 0.1 kg/cm 2 to 3 kg/cm 2 , the average particle size of the powder decreases while the particle size distribution gradually becomes more even. When the air pressure is at 0.1 kg/cm 2 , the particle size distribution appears to be 20–80 nm. When the air pressure increases to 0.5 kg/cm 2 and 1 kg/cm 2 , the particle size distribution becomes 20–50 nm and 20–40 nm respectively. When the air pressure increases to 3 kg/cm 2 , the average particle size becomes about 25 nm. To produce the nanosize nickel oxide powder, a spray pyrolysis system is specially designed. The raw material solution is fed into an inlet of the nozzle, while the compressed air is fed into the other inlet of the nozzle. And, the produced powder can be collected by bag filter in reaction furnace. ► A fabrication of powder with average particle size below 50 nm ► A spray pyrolysis system is specially designed and built for this study. ► The influence of concentration of solution on the properties of the powder ► The influence of air pressure on the properties of the powder