Zeta Potential and Hydrogen Production of Mesoporous Titanium Oxide

Mesoporous C-N doped TiO2 (MCNT) was prepared and Pt was deposited on the surface. Hydrogen production capability of the material with UV light, visible light, and sunlight was studied. The zeta potential was measured before and after hydrogen production. It was found that MCNT could be used to produce hydrogen gas. The highest hydrogen production was reached when MCNT prepared at 500 °C was irradiated with sun light. Zeta potential after UV and sun light irradiation tends to increase compared to before the irradiation. When the zeta potential showed negative value which indicates the presence of thin diffuse double layer, large amount of hydrogen was generated. However, when dispersed particles after irradiation of UV or sun light showed larger zeta potential, small amount of hydrogen was produced. This suggests that thick diffuse double layer formed on the surface of TiO2 particles may decrease the wettability between solution and particles.