Design And Properties Of Iron Based Organic Framework Visible Light Catalytic Materials

Due to the rapid development of global social economy,excessive CO₂ emissions have a negative impact on the ecological environment and human survival.China plays an important role in global governance and has proposed a“dual carbon”target,namely“emission peak”and“carbon neutrality”.The photocatalytic reduction of CO₂ by solar energy is green and pollution-free,and has a huge advantage for solving environmental problems.The existing iron-based metal-organic frameworks have disadvantages such as weak visible light utilization rate and low catalytic reduction activity.Therefore,through the research of this subject,the iron-based metal organic framework is designed and synthesized to improve its utilization of visible light,reduce the recombination of electrons and holes to enhance the photocatalytic ability,and provide effective solutions to environmental pollution and energy shortage problems.The main research contents and results are as follows:（1）NiFe₂O₄@N/C/SnO₂ nanocomposites were synthesized by solvothermal synthesis of Fe Ni-MOF as catalyst precursor and combined with SnO₂.Remarkably,using[Ru（bpy）₃]Cl₂·6H₂O as a photosensitizer,in combination with triethanolamine（TEOA）and acetonitrile（Me CN）,acting as a sacrifice agent,CO₂ was reduced to CO under light irradiation.The yield of CO is 2057.41μmol g^-1 h^-1.The excellent photocatalytic performance of the mentioned catalyst may be attributed to the strong interaction between NiFe₂O₄ and SnO₂ and to the formation of the carbon-nitrogen layers.Notably,NiFe₂O₄@N/C/SnO₂ also displayed a high magnetic sensitivity,which is conducive to the recovery of the catalyst.（2）A simple hydrothermal method was used to simultaneously ammoniated and sulfided NiFe-MOF.The influence on the CO yield and morphology of the material was investigated by changing the material ratio of 2-amino-terephthalic acid and p-mercaptoterephthalic acid.The results of photocatalytic reduction experiments showed that when the ratio of 2-amino-terephthalic acid and p-mercaptoterephthalic acid was 2:1（N2S-NiFe）,the catalytic activity of CO₂ reduction was the highest,and the CO yield was as high as 1.24×10⁴μmol g^-1 h^-1.Through analysis,it is found that vulcanization and amination can improve the material’s light absorption ability,enhance the adsorption of CO₂ and produce defects,expose more catalytically active sites.（3）N2S-NiFe was mixed with S.oneidensis MR-1 to construct a material-microbial composite system.A series of tests were carried out to characterize the internal element composition,valence distribution and morphology of the material,which confirmed the successful construction of the composite system.The material can efficiently convert CO₂ into CO by illumination,and the CO yield reached 2292.64μmol g^-1 h^-1.