Converting of CO into low-molecular-weight organic compounds with the TiO/ZrO composites under solar irradiation.

The preparation of a specially modified titanium dioxide/zirconium oxide (TiO/ZrO) composite and its subsequent application using a unique method are described. Specifically, after the whole surface of the composite was covered with a very thin layer of water, solar light was irradiated onto it. This method is unique because the reduction of CO was performed in air (gas phase). The light source was real solar light. In this study, novel composites comprising nanometre-sized TiO and micrometre-sized zirconium oxide (ZrO) increased the amount of reduced CO. And, suitable weight ratio of TiO/ZrO was 6/4-5/5. Thin water layer on the composite offered catalytic-reaction medium, and, catalytic-reaction cite existed at interface of TiO and ZrO particles, and, this reaction was catalytic reaction enhanced by photocatalytic effect. A large amount of reduced products (maximum: approximately 300 μmol/(g·300 s) of formaldehyde and methanol)was obtained under only 300 s of irradiation of solar light.