Method for stably preparing nano-copper powder

The invention relates to a method for stably preparing nano-copper powder. The method for stably preparing the nano-copper powder includes the following steps that first, copper sulfate is added into pure water, a solution of copper salt with the concentration between 0.1 mol/L and 1.0 mol/L is prepared, and the solution of copper salt is placed in a reactor to be preheated; second, ammonia water with the mass percentage concentration between 15 percent and 30 percent is dripped into the solution while the solution is stirred, so that a blue turbid solution is formed, and then a solution of the hydrazine hydrate reducing agent with the mass percentage concentration between 70 percent and 90 percent is dripped in the solution; third, a dispersing agent solution is injected in before all the hydrazine hydrate completely react; fourth, generated brick-red powder is filtered and washed, and the powder is first washed with treated pure water, then washed with ethyl alcohol and finally soaked in an ethanol solution containing coating agents; fifth, the supernate is poured out, and then the copper power is obtained through vacuum drying. The method for stably preparing the nano-copper powder has the technical advantages that the method is good in repeatability and stable in reaction process after the system is amplified, and the detection result is consistent with that of a small system.