Preparation of ultra-fine ZnO powders by interfacial stripping precipitation method

Zinc oxalate powders were prepared through interfacial stripping precipitation method with P204 diluted by tetrachloride carbon as an extractant, and oxalic acid ethanol aqueous solution as a reextractant and precipitator. Zinc oxide powders were obtained by decomposing zinc oxalate powder at 450°C. The results showed that the P204 contents in the oil phase, oxalic acid, ethanol contents in the water phase and temperature had obviously influence on the size distribution of zinc oxide powders. ZnO powders with the average size of about 32 nm was obtained under an optimum condition with P204 35% (v/v) in oil phase, H₂C₂O₄ 0.3 mol/L and ethanol 80% (v/v) in water phase, reaction temperature 20°C. The kinetics study of the photocatalytic oxidation about ZnO showed the optimum catalyst loadings was 0.4g/L.