Radiocatalytic H2 production with gamma-irradiation and TiO2 catalysts

Hydrogen gas (H2) was produced by gamma-irradiation of pure water in the presence of various TiO2 catalysts. Most catalysts used in this work largely enhanced the radiolytic decomposition of water and subsequent production of H2. The different activity of catalysts was characterized by X-ray diffraction (XRD) patterns and by electron paramagnetic resonance (EPR) spectra. The addition of methanol as a sacrificing agent further increased the H2 production by scavenging hydroxyl radicals and the scavenging activity was directly identified using an EPR/spin-trapping technique. Among the catalysts studied, nanosized TiO2 (nTiO2) showed an excellent activity in the production of H2. Furthermore, the addition of EDTA instead of methanol largely increased the H2 production. This is quite promising since waste compounds such as EDTA can be removed with concomitant H2 production. (author)