PNNL

Abstract

Titanium oxide (TiO2) is produced and used on the multi-megaton/year scale in a wide range of products where the nature of the optical properties is paramount, such as the cosmetic industry and the pigment industry. Also, TiO2 has been studied extensively for its activity in the photocatalytic splitting of water for the production of hydrogen as a clean source of energy. The potential market of an especially efficient material for splitting water is obviously enormous. Scott Elder and his colleagues at Pacific Northwest National Laboratory were inspired by recent research that has shown that TiO2 can photoelectrolyze water to produce H2. The potential for converting light to electrical energy or splitting water by solar-driven bandgap excitation is intriguing, but the problem is that TiO2 is limited in terms of its bandgap energy (3.2eV), which is outside of the most intense region of the solar spectrum. Elder and his team have come up with a way to engineer TiO2 at the nanoscale to give the material tunable photophysical properties that could eventually be exploited for practical solar energy conversion applications.