High Pressure High Temperature Annealed TiO2 for Photocatalytic Biomass Reforming

Hydrogen gas is considered a form of green energy due to its clean emissions. However, about 95% is produced from unsustainable processes like methane steam reforming and coal gasification. Photocatalytic generation of hydrogen from renewable feedstocks such as biomass or landfill-derived methane will increase the sustainability of hydrogen gas production. This project focuses on the synthesis, characterization, and photocatalytic activity of annealed Anatase phase TiO2 nanoparticles. TiO2 is stable under catalytic conditions and has high photocatalytic activity. However, its large bandgap of 3.2 eV corresponds to activity under UV irradiation which comprises about 5% of incident solar radiation on Earth. We reduce this large bandgap to extend to the visible light range by inducing electronic and geometric defects in the TiO2 structure by annealing Anatase under Hydrogen in high pressure and temperature conditions. This contributes to the formation of oxygen vacancies and Ti3+ centers, which can form donor and acceptor levels respectively in the electronic structure. Induced geometric defects affect the charge recombination process. Both electronic and geometric defects influence the reactivity of TiO2 in photocatalytic applications.