PREPARATION METHOD OF NANO-POWDER BY CHEMICAL PRECIPITATION METHOD

摘要

A means capable of accomplishing a high reduction ratio of 92% or more at low temperature without using an excessive amount of the reducing agent or without heating the aqueous solution to a high temperature of 156 deg.C when preparing nanosilver powder from a silver nitrate(AgNO3) aqueous solution using dimethylformamide as a reducing agent by chemical precipitation method is provided. In manufacture of a nanosilver powder from a silver nitrate aqueous solution by a chemical precipitation method, a method of preparing nanosilver powder with uniform particle size comprises performing a reduction reaction of the mixture by adding dimethylformamide as a reducing agent to the mixture in the state that tetrahydrofuran as a dispersant and a reduction aid is added to the silver nitrate aqueous solution in advance. The tetrahydrofuran is added such that a mole ratio of silver to tetrahydrofuran becomes 1:1 to 1:3. The aqueous solution contains a silver concentration of 1 to 50 g/L, and the reaction is performed at a temperature of room temperature to 50 deg.C. The dimethylformamide that is a reducing agent is added such that a mole ratio of silver to dimethylformamide becomes 1:0.6 to 1:0.8.