Ordered Mesoporous TiO₂: The Effect of Structure, Residual Template and Metal Doping on Photocatalytic Activity

Using a series of ordered mesoporous TiO2 (om-TiO2) with and without Ce or Cu doping, the effects of structure, metal doping and residual template species in the structure are systematically evaluated in terms of products formed during a CO2 photoreduction process. It is found that the ordered mesoporous structure contributes significantly in the hydrogen evolution reaction from the splitting of gaseous water. No cocatalyst was needed to achieve high hydrogen yields. While carbon-containing products are also observed, the presence of remainders of the organic template used in the synthesis process does not allow an unambiguous identification of the source of products. Small amounts of metal doping do not majorly influence the hydrogen evolution, thus the mesoporous structure can eventually be identified as the main cause for the improved performance.