Controlled synthesizing method for nano-manganese oxide with different shapes and sizes

The invention discloses a controlled synthesizing method for nano-manganese oxide with different shapes and sizes. By taking phosphoric acid as a shape and size regulator, the phosphoric acid is reacted with a permanganate aqueous solution to synthesize nano-manganese oxide, wherein the molar ratio of permanganate and phosphoric acid is 1: (0.5-16). The method is of relatively high controllability, and can control shapes of nano-manganese oxide directionally to obtain flower-like and rod-like nano-manganese oxide with uniform shapes, separately. Meanwhile, the raw materials are cheaper and safer, and are unlikely to corrode equipment; the diameter of the synthesized nano-manganese oxide flower is smaller than 400nm, and the minimum diameter reaches 50nm; the diameter of the synthesized nano-manganese oxide rod is 18.9-28.8nm, and the length is 283-425nm; and the prepared product is higher in specific surface area and higher in adsorption capacity. The synthesizing method has the advantages of being simple in process, cheap and easy for scaled production and the like.