The invention provides a method for preparing a
boron nitride nanowire by
cracking of a
polymer. The method comprises the following steps: synthesizing a polyalkylamino
borazine precursor according to the prior art:
grinding the precursor under the protective condition of
inert gas and screening the grinded precursor through a 1000-mesh
sieve; placing the precursor
powder in a
graphite boat, rising the temperature to 100-200 DEG C at the speed of 3-10 DEG C / min in the presence of high-pure
nitrogen in a tubular furnace, and then insulating for 1-3 hours; rising the temperature to 500-700 DEG C at the speed of 3-10 DEG / min, and then insulating for 1-3 hours; at the
atmosphere of
nitrogen, heating to 1000-1600 DEG C at the rising speed of 3-10 DEG C / min, then insulating for 0.5-5 hours, and then cooling along with the furnace so as to obtain the
boron nitride nanowire. The
diameter of the
nanowire prepared by the method is about 13-18 nm and is evenly distributed, no catalyst is used, preparation temperature is low, and energy is saved, thereby reducing the cost; and the method is simple in process, is convenient for operation and is easy to achieve large scale; and as a structure reinforced material, a
semiconductor material, a wave-transparent material and the like, the prepared
boron nitride nanowire has a good prospect of application.