Research On Preparation Of MOFs-based Composite Photocatalyst And CO₂ Reduction

Based on the high specific surface area and high CO₂ adsorption capacity of MOFs materials,combined with traditional inorganic semiconductor materials,a Cu/TiO₂/HKUST-1 composite catalyst was constructed.From the perspective of the three-dimensional framework of MOFs materials inhibiting the agglomeration of quantum dots during catalysis process,CuO@UiO-66 composite catalysts were prepared.Through a series of characterizations,the morphology,structure,optical properties,chemical composition and charge separation of the composite catalyst were analyzed,And systematically studied Cu/TiO₂/HKUST-1 and CuO@UiO-66 photothermal catalytic reduction of CO₂ charge transfer and activity improvement mechanism.The Cu nanoparticles were loaded on TiO₂ by hydrothermal method,and HKUST-1was modified on the surface of Cu/TiO₂ by in-situ synthesis to prepare Cu/TiO₂/HKUST-1composite photocatalyst.HKUST-1 provides active sites for the adsorption and conversion of CO₂ into formic acid,and at the same time promotes the separation of photo-generated charges.Cu nanoparticles can effectively transfer the photogenerated electrons of TiO₂ and provide active sites for the reduction of CO₂ to methanol.The yields of the composite for photothermal catalytic reduction of CO₂ to methanol and formic acid at a reaction temperature of 120℃are 202.00μmol g^-1 h^-1 and 53.67μmol g^-1 h^-1,respectively,which are 2.14 and 9.81 times of the photocatalytic yields of methanol and formic acid,2.51 and9.37 times the yields of thermally catalyzed methanol and formic acid,respectively.CuO@UiO-66 composite catalyst was prepared by complex oxidation method.The three-dimensional framework of UiO-66 effectively inhibits the agglomeration of CuO QDs under traditional photocatalysis and high temperature,and the composite catalyst can significantly enhance the efficiency of photo-generated charge transfer and separation.The composite CuO@UiO-66 showed good photothermal catalytic stability.Under 120℃and visible light irradiation,the yield of reducing CO₂ to methanol in an aqueous solution of2.00%CuO@UiO-66 is 487.67μmol g^-1 h^-1,which is 3.00 times that of photocatalysis and2.70 times that of thermal catalysis,respectively.Figure 44;Table 7;Reference 102...