Effect of Reaction Driving Force on Copper Nanoparticle Preparation by Aqueous Solution Reduction Method

Abstract

The preparation of copper nanoparticle is currently an area of intensive scientific research, as copper nanoparticle is viewed as possible replacements for Ag and Au particles in certain potential applications such as catalyst and conductive paste. 1–3) Currently, many well-known copper nanoparticle preparation methods exist, such as radiation, microemulsion, supercritical, thermal reduction, sonochemical reduction, laser ablation, metal vapor synthesis, and chemical reduction methods, as well as vacuum vapor deposition and supercritical techniques. 4) Among these, the aqueous solution reduction method is a widely adopted approach due to its advantages such as convenient operation, high yield rate and quality, low equipment requirement and controllability. In previous research, much work has been completed to explore the optimal conditions of nanoparticle preparation. However, the reaction mechanism has been seldom reported, which can help elucidate the reduction process. Therefore, the effect of different reductants on copper nanoparticle preparation was investigated to explore the reaction mechanism. C6H8O6 ,H 3PO2 ,T i 2(SO4)3 and NaBH4 were used as the reductants. 2. Principle of Experiment The reduction of Cu 2þ to Cu atom is the result of redox reaction, in which electrons are transferred from the reductant to Cu 2þ . To discuss the reaction mechanism, reaction driving force (� E) was introduced in this paper. During the redox reaction process two half-cell reactions take place. One is the reduction of Cu 2þ to Cu atom, and the other is the oxidation of reductant. The oxidation half-cell reaction