Coal-based Graphene Oxide And Composite Study On Photocatalytic Reduction Of CO₂

Photocatalytic reduction of CO₂ is recognized as one of the most promising pathways to realize green conversion and utilization of CO₂. The key to conversion efficiency of CO₂ is to develop photocatalysts with good photo-response and high efficiency. With the emergence of a new two-dimensional carbon material graphene, the unique molecular structure and chemical properties, and between graphene and metal or semiconductor synergistic effect, and provides a new research pathway for studying the effective catalyst.Coal is an organic compounds of containing polycyclic aromatic hydrocarbon structure, which can be used as carbon source for development and preparation of coal-based carbon materials. This paper investigated coal-based graphene oxide controllable preparation and modified methods, and coal-based graphene oxide application in the photocatalytic CO₂ process. The thesis focused on studying catalytic properties of coal-based graphene oxide and composite materials in CO₂ photocatalytic process. The study mainly includes the following two aspects:（1） In coal-based graphene oxide preparation and photocatalytic properties studies, Inspected the coal metamorphism on metal elements in coal and coal-based structure of the graphene oxide and photocatalytic properties. The results show that organic structure of different metamorphic degree coal can reconstructed by catalytic heat treatment, followed by coal-based graphene oxide prepared by ultrasound-assisted Hummers method. Coal-based graphene oxide prepared using different metamorphic degree coal show no obvious difference in morphology and structures by detection analysis. The photocatalytic activity of Huainan coal-based graphene oxide is the highest compared with others, and the yield of methanol is 20.49 μmol/g.cat.（2） Preparation and photocatalytic properties of coal-based graphene oxide composites research. Graphene oxide as the carrier obtained TiO₂/GO, Cu/TiO₂/GO and Fe/TiO₂/GO were successfully prepared via hydrothermal method. The results indicate that all the photocatalytic activity of coal-based graphene oxide composites are superior to coal-based graphene oxide. When TiO₂/GO load than for 7:3, The yield of methanol reaches up to 60.99 μmol/g.cat, which is 3 times higher than that of coal-based graphene oxide; when Cu load volume for 2%, The yield of methanol reaches up to 94.79 μmol/g.cat; when Fe load volume for 4%, the yield of methanol as high as 126.28 μmol/g.cat, which is about 6-fold that of coal based graphene oxide.