Hydrogen generation by laser irradiation of colloids of iron and beryllium in water

The hydrogen generation under irradiation of aqueous colloids of iron and beryllium nanoparticles by 10-ns pulses of the first harmonic of a Nd : YAG laser with an energy density of about 80 J cm⁻² in the solution is experimentally investigated. The partial hydrogen content in the atmosphere above the colloidal solutions of nanoparticles first increases with increasing irradiation time and then reaches a stationary level (400 − 500 Torr). The hydrogen generation rate, being nonzero in the case of irradiation of pure water, passes through a maximum with an increase in the nanoparticle concentration. The results obtained are discussed in terms of the dissociation of water molecules under a direct electron impact from the optical breakdown plasma formed in the liquid. (paper)