Research On The Preparation Of Sn Nanoparticles By Chemical Reduction Method

Sn nanoparticles have shown a huge potential in the lead-free solder, ink-jet printing, lithium ion battery electrodes and other fields due to its low melting p oint and high lithium storage capacity. the most common preparation method for Sn nanoparticles is chemical reduction, which can be divided into PVP system and Phen(1,10-phenanthroline) system according to the classification of the surfactants. Sn nanoparticles have been mainly used in the field of lithium ion battery electrodes. However, there have been only a few reports on low temperature sintering of Sn nanoparticles. In this research, we have synthesized Sn nanoparticles with different sizes based on the two preparation systems, and defined the influence of sintering process on the microstructure and electrical conductivity of Sn nanoparticles sinterIn the PVP system, we have investigated the influence of the content and molecular weight of PVP on the Sn nanoparticles sizes. The experimental results showed that the sizes of Sn nanoparticles decreased with the increase of the contents of PVP and the decrease of the molecular weight of PVP. When the content of PVP was 1.0 g and the molecular weight of PVP was 24000, the average size of Sn nanoparticles dropped to 23 nm.In the Phen system, parameters like solvent, the addition way of reductants, the content of Phen and the concentration of reactants have been fully investigated. It indicated that the sizes of Sn nanoparticles decreased with the increase of the content of Phen and the decrease of the concentration of reactant. In order to prepare the minimum average size(30.4 nm) of Sn nanoparticles, the optimal experimental condition was under which the content of Phen was 4.5g and the concentration of reactant was 0.01 g/ml.We have also investigated the relations of conductivity with sintering time and sintering temperature. The experimental results showed the resistivity of Sn nanoparticles decreased with the lengthening of the sintering time and the increase of sintering temperature, which was more evident when the sintering temperature was relatively low. In addition, the resistivity of Sn nanoparticles was 141.09 μΩ·cm after sintering at 150 ℃ for 20 min, which was fourteen times higher than the bulk Sn resistivity(11 μΩ·cm). When the sintering temperature was 200 ℃ and the sintering time was 60 min, the resistivity of Sn nanoparticles sinter dropped to 21.50 μΩ·cm, which was as twice as the bulk Sn.