**3.1 Size and morphologies of Field's alloy nanoparticles**

The size and morphologies of synthesized Field's alloy nanoparticles using nanoemulsion method were investigated by TEM. **Figure 2** showed the TEM images of the as-prepared Field's alloy particles after boiling the Field's alloy pellets in PAO at 180°C for 10 min (**Figure 2A**) and 2 h (**Figure 2B**), respectively. When the boiling time increases, the size of particles would decrease and became more and more spherical. After 10 min, the particles have irregular shapes and with the size range from 200 to 500 nm. As the time increases to 2 hours, the particles showed spherical shapes with the size of about 20 nm. **Figure 2C** showed the plot of reaction time versus the size of particles. After 2 hours, even though the reaction time increase (such as 5, 10, or even 20 h), the particles size did not have too much change, which was still close to 20 nm.
