Photocatalytic H_2 production from methanol aqueous solution over titania nanoparticles with mesostructures

摘要

The photocatalytic hydrogen production over TiO_2 nanoparticles with mesostructures has been studied using CH_3OH as a sacrificial reagent. The effects of the calcination temperature, Pt-loading, amount of TiO_2 and methanol as well as irradiation time on the H_2 evolution rate were investigated in detail. The results indicated that the as-synthesized TiO_2 nanoparticles without calcination, having a large specific surface area (438 m~2/g) and small crystallite size (2.3 nm) dispersed among the amorphous mesoporous domains, exhibited the best photocatalytic activity for H_2 production compared with the samples calcined at different temperatures and the commercial photocatalyst P25 (Degussa, Germany) under the same photoreaction conditions. The presence of mesostructured TiO_2 nanoparticles with a uniform dispersion of the co-catalyst (Pt) has resulted in an effective, faster charge separation, which, in turn, leads to a higher photocatalytic activity for H_2 production.