A PROCESS OF ENHANCING PHOTOCATALYTIC ACTIVITY OF A ZINC OXIDE AND A COMPOSITION COMPRISING ZINC OXIDE WITH ENHANCED PHOTOCATALYTIC ACTIVITY

摘要

A method for increasing the photocatalytic activity of zinc oxide, a method for preparing a zinc oxide nano-plate crystal, a tooth whitening composition containing the zinc oxide nano-plate crystal, and an organic pollutant degrading composition containing the zinc oxide nano-plate crystal are provided to improve the whitening effect of tooth and the degradation effect of organic pollutants. A method for increasing the photocatalytic activity of zinc oxide comprises the step of preparing a zinc oxide nano-plate crystal whose crystal plane(0001) forms a plate. Preferably the zinc oxide nano-plate crystal has an average thickness of 50 nm or less and an average aspect ration of 20 or more. A method for preparing a zinc oxide nano-plate crystal comprises the step of inducing the growth of crystal by using a zinc oxide nanoparticle as a crystal nucleus in the zinc oxide crystal growing solution where citric acid or its salt is added.