Controllable method for preparing nano zinc oxide powder

The invention relates to a controllable method for preparing nano zinc oxide powder, which is characterized by adopting the salt of inorganic zinc nitrate and the chelating agent of citric acid which has the complexing function as the raw materials and the ethylene glycol, the polyethylene glycol, or the polyvinyl alcohol as the surfactant. The controllable method for preparing the nano zinc oxide powder specifically comprises the following steps: preparing solution from the zinc nitrate, the citric acid and the surfactant according to a certain molar ratio, reflowing the solution with water bath, aging, gelatinizing, drying and annealing to obtain the nano zinc oxide powder with single component and uniform distribution of the agglomeration-free particle of 20-100 nm. The nano zinc oxide powder has low cost, high quality and high yield, is prepared with simple equipment and can realize the industrial production easily.