The invention provides a method for preparing a borazon nano
pipe by the
magnesium-thermic reduction, belonging to the inorganic nano material field. In the prior method for preparing the borazon nano
pipe, the problems of low yield and high cost exist. The method of the invention comprises the following steps that : (1) under
argon shield, according to the mol ratio of 1:1-3:0.01-0.1, borazon,
magnesium and
ferrous salt are ground, mixed and screened; (2) under
argon shield, the screened mixture is heated, and at a temperature of between 900 and 1,200 DEG C,
argon gas is closed and the
ammonia gas is filled, and when the temperature reaches between 1,200 and 1,600 DEG C, the temperature is maintained for 1 to 5h; (3) after the temperature decreases to the
room temperature, the mixture is immersed in
nitric acid, the product obtained has impurities removed, and the borazon nano
pipe is obtained. The method of the invention has the advantages of simple process, easy control and amplification of reaction, low cost, high yield and
uniform size and high purity of the prepared borazon nano pipe.