Abstract
The highly porous, three-dimensionally well-connected through-pore structure of TiO 2 aerogels is proven a superior material form for applications in photocatalytic water splitting for hydrogen production. At the reaction temperature of 30 °C, the specific hydrogen evolution rate achieved by the TiO 2 aerogel is 3.40 and 9.63 times those obtained by hydrothermally prepared TiO 2 nanocrystals and commercial P25 TiO 2 nanoparticles, respectively. Decoration of Pt nanocrystals onto the backbone of the TiO 2 aerogel leads to a one-order of magnitude improvement in hydrogen evolution rate over the plain TiO 2 aerogel. Two methods are developed for the Pt decoration: a polyol process and an immersion-calcination-reduction process. The latter produces smaller sized Pt nanocrystals of around 1.9 nm, versus 4.7 nm from the polyol process, and achieves the same level of maximum specific hydrogen evolution rates as the polyol process at only a 1/10 Pt loading. © 2011 The Royal Society of Chemistry.