A method for producing polygonic Zn oxide platelets having a median specific surface area of more than 25 square meters per gram, in controlled size and morphology, the method comprising: preparing a medium including Zn or its compounds at a concentration within the range between 1.55 and 7.75 moles of Zn/L, in a medium suitable to substitute Zn ions by releasing free protons thereby forming a complex structure including Zn; agitation of the medium in a vessel at a temperature within the range between 50 and 320° for a duration up to 10 hours to obtain a suspension; filtering the suspension to obtain a filtrate including solid particles; drying and then calcination of the dried filtrate; wherein the agitation is performed with one or more radial flow impellers so that the Reynolds' number in the vessel is higher than 2500 and lower than 10000.