Effect of alumina on the enhancement of hydrogen production and the reduction of hydrogen peroxide in the γ-radiolysis of pure water and 0.4 M H2SO4 aqueous solution

The H2 and H2O2 produced by 60Co γ-radiation at room temperature were measured in pure water and 0.4 M H2SO4 aqueous solution with alumina powder. By increasing the addition of alumina powder, a strong reduction of H2O2 concentrations in the solutions was obtained, and the final product H2 yields were correspondingly enhanced. These enhancement and reduction effects were diminished in the subsequent γ-radiation when irradiated alumina powder was used. The effects were reversibly restored by washing the irradiated powder with purified water. In 0.4 M H2SO4 solution with alumina powder, the H2 yields increased by increasing the absorbed dose rate in the region of 1–5 kGy/h. The radiation-enhanced H2 production correlated with the reduction of H2O2 concentration could be brought about by the reduction of H2O2 molecules and OH radicals in the solutions due to alumina powder.

► H2 produced by γ-radiolysis in water or 0.4 M H2SO4 increased by adding alumina. ► In contrast, counter part H2O2 decreased with increasing the alumina powder. ► The enhanced H2 yields were strongly correlated with the reduced H2O2 yields. ► This correlation could be originated by adsorption of OH radicals on alumina surface. ► The H2 yields increased with the dose rate of γ-radiation in 0.4 M H2SO4 with alumina.