Stable products of laser-induced breakdown of aqueous colloidal solutions of nanoparticles

The formation of stable products of water decomposition under laser exposure of aqueous colloidal solutions of nanoparticles is experimentally studied. Laser exposure of colloidal solutions leads to formation of H2, O2, and H2O2. The dependence of the yield of these products depends on the energy density of laser radiation inside the liquid and concentration of nanoparticles. The ratio H2/O2 depends on laser fluence and is shifted towards H2. There are at least to sources of H2O2, namely, laser-induced breakdown plasma and ultrasound induced by laser pulses in the liquid. The formation of both H2 and O2 is tentatively assigned to direct dissociation of H2O molecules by electron impact from laser-induced plasma.