Photoreduction of carbon dioxide by graphene–titania and zeolite–titania composites under low-intensity irradiation

As it is the most important of the greenhouse gases, the utilization and reduction of carbon dioxide have attracted a great attention. As compared to the technological demands for carbon capture and storage (CCS), carbon dioxide reduction is a safe and effective way to convert carbon dioxide to fuel. In this research, two different catalysts, graphene–titania and zeolite–titania, are used to achieve the carbon dioxide reduction. The characteristics of these materials are analyzed by Brunnauer–Emmett–Teller, X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet–visible, scanning electron microscope and transmission electron microscopy. Because of the different features of the catalysts, various products can be generated through different pathways. Formic acid and methanol are the final products when graphene is used as the catalyst, but only methanol can be generated when zeolite–titania is used as the catalyst. The reaction mechanisms and pathways are discussed.