New progress has been made in the synthesis of hollow nanomaterials by solids. The use of the Kirkendall effect (Kirkendall effect) to synthesize hollow nanomaterials is a hot topic in the field of nanomaterial preparation science. In the experiment, the hollow structure of the product obtained by using the Kechdal effect generally does not exceed 500 nm. Nanomaterials with larger hollow structures can significantly improve the carrying capacity especially in the fields of drug sustained release and delivery. Recently, researchers at the Institute of Solid Physics, Hefei Institute of Material Science, Chinese Academy of Sciences have successfully obtained manganese oxides (Mn3O4, Mn5O8, Mn2O3) with hollow tetradecahedrons with larger hollow structures using hydrothermal methods. Through careful analysis of the experimental process, researchers believe that the formation of this hollow structure depends on the Kegendahl effect. In the initial stage of the reaction, the metal manganese reacts with the solution hydrothermally to form a tetrahedron of Mn (OH) 2. At the end of the reaction, during contact with air, the Mn (OH) 2 tetrahedron can be oxidized by oxygen in the air, and the Kendall effect occurs. It is worth noting that during this reaction, the lattice structure shrinks when changing from Mn (OH) 2 to Mn3O4 (due to the loss of water during the transition, the volume shrinks by about 42%). The shrinkage of this structure on the one hand speeds up the reaction, and at the same time increases the free path of manganese migration, so that the Kirkendall effect can act in a larger space. The researchers also studied the magnetic and electrochemical properties of the hollow manganese oxide. These results show that this material has potential application prospects in many fields such as capacitors, drug delivery and sustained release, environmental treatment and catalysis.
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