Solar light photocatalytic hydrogen production from water over Pt and Au/TiO2(anatase/rutile) photocatalysts: Influence of noble metal and porogen promotion

Hydrogen production from water under artificial solar light irradiation was performed over a series of Pt and Au/TiO2(anatase/rutile) photocatalysts. Different TiO2 supports with varying anatase/rutile contents were compared, based on either sol–gel synthesis or commercial TiO2. The influence of template promotion on sol–gel TiO2 synthesis has been studied using different porogens or templates. Among various factors influencing the hydrogen evolution efficiency, it was pointed out that the following parameters were crucial to enhance H2 evolution: (i) the nature and content of the metallic co-catalyst, (ii) the surface, crystallographic, and porosity properties of the TiO2 anatase/rutile support, (iii) the anatase/rutile ratio, (iv) the metal–support interactions, and (v) the relative amount of methanol added as a sacrificial reagent. The influence of these different factors was studied in detail. In optimized conditions, important H2 production efficiency (120 μmol/min) was obtained over days without deactivation and with very low amounts of methanol.