CeO/CuO/TiOheterojunction photocatalysts for conversion of COto ethanol.

An attempt to reduce COemissions has led to the development of CeO/CuO/TiOheterojunction photocatalysts for photoconversion of COto useful products, e.g. ethanol. Composite photocatalysts were simply prepared by mixing TiO(P25) with different mass ratios of CeO(1 wt%) and CuO (2 or 3 wt%) by ball milling. The prepared photocatalysts had uniformly distributed CeOand CuO phases, throughout the TiOphase. The integration of CeOand CuO into TiOat 1 wt% CeOand 3 wt% CuO produced a composite, with a reduced band gap of 2.88 eV, allowing absorption of lower energy light and a lower electron-hole recombination rate. The 1%CeO/3%CuO/TiOphotocatalysts yielded ethanol at 30.5mol gh, almost three times higher than the yield from pure TiO. This improved COconversion efficiency was due to contributions from properties of both additives: CeOincreased light absorption, while CuO acted as an electron trap and enhanced COadsorption. In addition, the heterojunction at the interfaces facilitated the photogenerated charge separation, which, in turn, increased the charge participation in the catalyzed conversion reactions.