| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing granular gold nanoparticles of≤100 nm which is safe, is environment-friendly and has a narrow particle size distribution without using a gold compound such as a harmful chloroauric acid and a reducing agent by a simple method. SOLUTION: Gold is anode-oxidized in an aqueous solution of carboxylic acid or carboxylate other than oxalic acid and the salt thereof, and the obtained porous film is immersed into water, e.g., for one week. In this way, natural decomposition of the porous film occurs, thus a gold nanoparticle-dispersed liquid can be obtained. By subjecting the dispersed liquid to centrifugal separation, filtration or the like, the gold nanoparticles are separated and recovered, and are, when necessary, dried so as to obtain the gold nanoparticles. As the carboxylic acid and carboxylate, citric acid, lactic acid, tartaric acid, malic acid, and their salts are preferable. Further, the potential applied to a gold electrode is preferably controlled to about +1.5 to 11 V with respect to a hydrogen standard electrode potential. COPYRIGHT: (C)2011,JPO&INPIT |
