A Newly Developed Method of Direct Hydrogen Production from Seawater Using Femtosecond Pulse Laser

抄録

The direct production method of H₂ gas from seawater using femtosecond pulse laser was developed. This approach uses the photolysis triggered by multiphoton absorption of H₂O molecules and does not emit greenhouse or harmful gas such as CO₂ and Cl₂. In this study, direct H₂ production from seawater without desalination was demonstrated, and influences of focusing lens and salinity on H₂ production were experimentally revealed with a gas chromatograph. Aqueous solutions with moderate salinity (0.1-4%) showed a positive effect on H₂ production owing to nonlinear optical effects by ultrashort laser pulses, while excessive salt (the salinity of 7.0%) interfered with the ionization of H₂O.