Cu–TiO2 systems for the photocatalytic H2 production: Influence of structural and surface support features

Abstract

The influence of different TiO2 supports on the Cu active species has been studied. It was found that the photocatalytic H2 evolution is highly affected by the structural and electronic features of surface Cu species. Thus, metal dispersion and oxidation state appears strongly conditioned by the structural and surface properties of the TiO2 support. We have examined three TiO2 supports prepared by different synthetic methods; sol–gel, hydrothermal and microemulsion. In addition, we have induced structural and surface modifications by sulfate pretreatment over freshly prepared TiO2 precursors and subsequent calcination. Notably different copper dispersion and oxidation state is obtained by using these different TiO2 supports. From the wide structural and surface analysis of the catalysts we are able to propose that the occurrence of highly disperse Cu2+ species, the sample surface area as well as the crystallinity of the TiO2 support are directly related to the photocatalytic activity for H2 production reaction.