Preparation And Photocatalytic Degradation Of Graphene Oxide/Metal-Organic Framework Composites

With the rapid development of domestic industrial and agricultural economy,the content of organic pollutants in water keeps rising,which causes more and more serious health problems to human beings.Photocatalytic degradation is one of the effective ways to remove organic pollutants.The development of new porous materials with high efficiency is the core task of photocatalytic degradation technology.Metal-organic frameworks（MOFs）have many advantages,such as high specific surface area,high porosity and good thermal stability,etc.,and they are a kind of photocatalytic materials with great application prospects.In recent years,the synthesis and application of MOFs composites have also attracted extensive attention of scientific researchers.In this study,NH₂-MIL-53（Fe）/GO,NH₂-UIO-66/GO and TiO₂/NH₂-MIL-53（Fe）/GO composites were prepared by combining GO with MOFs,which had excellent visible light absorption and electron transport capacity,and TiO₂ with excellent photocatalytic degradation performance.The photocatalytic degradation of organic pollutants in water by these composites was investigated,and an efficient method for photocatalytic degradation of organic pollutants in water was established The main research contents and conclusions are as follows:1.NH₂-MIL-53（Fe）/GO composite was synthesized by solvothermal method with GO as matrix.Using rhodamine B（RhB）as the target pollutant,the photocatalytic degradation performance of the composite was investigated and the photocatalytic degradation conditions were optimized.The experimental results show that NH₂-MIL-53（Fe）/GO composite has a stronger photocatalytic activity for Rh B degradation than that of single NH₂-MIL-53（Fe）,and the best photocatalytic activity is shown when the doping amount of GO is 10 mg.In addition,NH₂-MIL-53（Fe）/GO composite showed excellent reusability in the cycle experiment,and the NH2-MIL-53（Fe）/GO composite still had good photocatalytic degradation effect after repeated use for 5 times.2.First,GO was mixed with the solvent N,N-2-methylformamide（DMF）,and then the mixture was added to the solution for the synthesis of NH₂-UIO-66.NH₂-UIO-66/GO composites were prepared by solvothermal method.Using norfloxacin（NOF）as the target pollutant,the photocatalytic degradation performance of NH₂-UIO-66/GO was investigated and the experimental conditions for photocatalytic degradation were optimized.The experimental results showed that,due to the abundant oxygen-containing groups on the GO surface as antenna,the electron transport efficiency of NH₂-UIO-66/GO is improved,so that NH₂-UIO-66/GO has a strong photocatalytic performance.Moreover,NH₂-UIO-66/GO has good reusability,which can be reused for more than 5 times,but still has a good degradation effect.Its degradation rate reached 83%.3.TiO₂/NH₂-MIL-53（Fe）/GO composites were synthesized by solvothermal method with GO as the matrix and TiO₂ doped in the synthesis process of NH₂-MIL-53（Fe）.The photocatalytic degradation of tetracycline hydrochloride（TC）with synthesized Ti_O2/NH₂-MIL-53（Fe）/GO was carried out and the photocatalytic degradation conditions were optimized.The photocatalytic degradation performance of TC by single material and composite materials with different Ti and Fe doping ratios was studied.The experimental results showed that,compared with NH₂-MIL-53（Fe）,the degradation performance of TC was significantly enhanced by TiO₂/NH2-MIL-53（Fe）/GO.When the doping ratio was Ti:Fe=1:1,the dosage of catalyst was 0.5 g/L,and the degradation rate of TC reached about93% after 120 min of light exposure.The degradation process follows the first-order kinetic model.The composite material can maintain good catalytic activity at pH=4-9,and is suitable for the purification and removal of antibiotics in different water bodies.It has a potential application prospect.