Coal⁃based graphene oxide / bismuth vanadate composite for photoreduction of CO2

Under the target of carbon neutrality and carbon peaking，the high value⁃added utilization of coal resources and CO2 resource conversion has become an important research topic， and the development of functional coal⁃ based materials for CO2 green conversion using coal as raw material shows a wide range of application prospects. A high⁃temperature graphitization and chemical oxidation strategy was employed to prepare the coal⁃based graphene oxide( CGO) using the Jincheng anthracite as the carbonaceous precursor，and the composite CGO / BVO was construc⁃ ted by growing BVO nanosheets on CGO through solvent evaporation，which could lead to an excellent photocatalytic CO2 reduction performance due to its unique 2D / 2D nanosheet structure. The structural，morphology and optoelectronic properties of the composites were determined by X⁃ray diffractometer(XRD)，transmission electron microscope (TEM)，UV⁃vis diffuse reflectance spectroscopy(UV⁃vis)and photoelectrochemical tests. It was demonstrated that the BVO nanosheets with narrow band gap and wide visible light absorption range can confer a good light absorption ability to the CGO / BVO composites. Meanwhile，due to the good physicochemical properties of CGO as a co⁃catalyst， it can effectively transfer the carrier produced by BVO nanosheets after photoexcitation. The synergistic effect generated by the sufficient contact between the two reduces the interfacial transfer resistance of the composite material， increases the separation and transfer rate of photogenerated electrons and the surface charge density of the photocata⁃ lyst，and thus facilitates the CO2 photoreduction to methanol reaction. When the mass ratio of CGO to BVO in the com⁃ posite reaches 10 ∶ 1，the methanol yield can reach 134.57 μmol / ( g∙h) ，which is 1.7 times higher than that of pure BVO nanosheets. This work provides an idea to the use of novel coal⁃based high value⁃added materials for the photo⁃ catalytic reduction of CO2 to methanol.