TW200727979A - A fabrication method for electrical conductive nano-powder - Google Patents

Abstract

This invention provides a fabrication method for electrical conductive nano-powder, in which antimony-doped tin oxide (ATO) or indium tin oxide (ITO) powder with diameter of 5-50 nm can be produced under high gravity; and there is no need to add acid or alkaline solution for adjusting the pH value or to use any volatile solvent during the fabrication process; therefore there is no problem of pollution of solvent. The nano-powder of the antimony-doped tin oxide (ATO) is made from an acid solution (A) and an alkaline solution (B). The acid solution (A) is formed by composing Sn-based halides and Sb-based halides, or by composing Sn-based halides and Sb-based oxides in such a way that its molar ratio (Sn/Sb) is between 1.5 and 1.9. The alkaline solution (B) is formed by composing sodium hydroxide with ammonium bicarbonate or ammonia water. The acid solution (A) and the alkaline solution (B) are ejected into a high gravity reactor, the feeding ratio of the acid solution(A) and the alkaline solution (B) is adjusted appropriately; wherein an instant reaction under the high gravity condition will take place so as to produce the paste of Sn-Sb hydrate that has a cream yellow color and has a stable pH value between 0.8-4.8, which then goes through the processes of water cleaning, filtering, ion-exchanging, and drying to become powder that is finally calcined at temperature of 550 DEG C to 800 DEC C for one to six hours so as to produce the antimony-doped tin oxide (ATO) powder with diameter of 5-50 nm with a low surface impendence of 10-2 to 10-1 Ω/&square. The process is quite simplified, and the production rate is improved. The indium tin oxide (ITO) powder can be made by the method similar to the method for producing (ATO).