Ultrafast laser-induced formation of AgO and Ag2O on silver

Ultrafast lasers have been widely used to texture materials, and while a lot of focus has been placed on controlling surface morphology, literature is lacking on ultrafast laser-induced surface chemistry, even though surface chemistry is essential in many applications. To better understand surface chemistry changes during ultrafast laser ablation, a femtosecond laser was used here to irradiate silver samples in air. The laser ablated craters were analysed with Raman spectroscopy and reveal the formation of Ag2O and AgO at different pulse energies and number of pulses. A mechanistic picture for the formation of both silver oxides and their transformation into Ag2CO3, Ag2SO3 and Ag2SO4 is proposed. Some laser-induced periodic surface structures LIPSSs were also observed on some craters, as well as nanoparticles arranged in concentric patterns.