Determination of pH in sol-coprecipitation process

In this paper, it is studied that how to determine the range of optimal pH value in sol-coprecipitation. The results show that then NH4HCO3 is used as precipitant for mixed solution of ZrOCl2. 8H2O and Y(NHO3)3 to carry on the sol-coprecipitation, the range of optimal pH value is 5~6.