**8. Laser ablation of silver nanoparticle in liquids**

Many researchers reported the preparation of silver nanoparticles in organic and inorganic solutions. Silver nanoparticles have biological, thermal, optical, and electrical properties. Hence, the synthesis of silver nanoparticles was presented using chemical and physical methods. Laser ablation of silver plate is an alternative and green method to prepare the

**Figure 2.** (a) TEM image of silver nanoparticle in oil and (b) UV-visible spectrum of silver nanoparticles produced using laser ablation.

silver nanoparticles, and nanoparticles grow in the unique form of organic and inorganic solutions without any agglomeration and collapsing. Silver nanoparticles were prepared in water, methanol, palm oil [22], coconut oil [71], pomegranate seed oil [72], polyvinyl alcohol (PVA) [28], and graphene oxide solution [73]. Silver nanoparticles were capped by chain fatty acid of oils, and the particle size was about 10 nm. When the ablation time increases, the size of particles decreases. Nanoparticles formed in the spherical shape that was obtained using transmission electron microscope image (**Figure 2a**). The efficiency of the colloidal absorption by silver nanoparticles for 355, 532, and 1064 nm laser beam depends on localized surface plasmon resonance or the plasmon band around 400 nm (**Figure 2b**). Hence, the maximum and minimum efficiency occurred in 355 and 1064 nm. Thus, the influence of the colloidal absorption was more prominent for shorter wavelength laser beam, leading to the conclusion that the formation efficiency and the size of nanoparticles decrease with decreasing laser wavelength.
