Photocatalytic hydrogen production using TiO2–Pt aerogels

Abstract

TiO2–Pt aerogel composites have been synthesized by mixing sol–gel titania with Pt colloidal suspensions followed by supercritical drying. The highest specific surface achieved with these materials ranged between 550 and 600m2g−1 before annealing and stayed relatively high, i.e. 162m2g−1, after calcination. The concentration of Pt nanoparticles ranged between 0.3 and 1.0wt.% while their size ranged between 5.75 and 6.5nm. These composites were employed as photocatalysts for room-temperature photocatalytic reforming of ethanol and hydrogen production. The highest hydrogen production rate, 7.2mmolH2h−1g−1, was obtained in the case of the smallest and most concentrated metal nanoparticles underlying the importance of the number of active sites on the TiO2–Pt composites. This rate of hydrogen production is relatively high and reflects the relatively high specific surface of the employed photocatalysts.