Study On Photocatalytic Degradation Of Dye Wastewater By Modified MOF Materials

MOFs materials have excellent characteristics include large specific surface area,adjustable physical and chemical properties and stable structure.In this paper,several MOFs materials with high adsorption and photocatalytic properties were prepared by hydrothermal synthesis.The adsorption and photocatalytic properties of the prepared MOFs were investigated by using acid red 3R?AR3R?as a simulated pollutant.The details are as follows:1)Fe-MOF with high photocatalytic activity was prepared by hydrothermal synthesis using terephthalic acid as organic ligand and Fe³⁺as the central ion.With the Xenon lamp as the light source,the AR3R removal rate reaches 100%after 45 min photocatalytic reaction.The capture agent experiments showed that·OH played a major role in the reaction system.2)Sn-MOF with high adsorption and photocatalytic activity was prepared by hydrothermal synthesis by using terephthalic acid as organic ligand and Sn⁴⁺as the central ion.After adsorption for 4 h,the adsorption amount of AR3R by Sn-MOF can reach102.60 mg·g^-1.The adsorption process conforms to the quasi-second-order kinetic equation and the Elovich equation.At the same time,the adsorption law is in good agreement with the Freundlich adsorption isotherm equation.With the Xenon lamp as the light source,the removal rate of AR3R reaches 100%after 15 min photocatalytic reaction.The capture agent experiments show that the·O₂ played a major role in the reaction system.3)Fe₃O₄@Sn-MOF with high adsorption and photocatalytic activity was prepared by hydrothermal synthesis by using Fe₃O₄ as the magnetic core,terephthalic acid as organic ligand and Sn⁴⁺as the central ion.After adsorption for 4 h,the adsorption amount of AR3R was 80.99 mg·g^-1.The adsorption process conformed to the quasi-second-order kinetic equation.The adsorption isotherm conforms to the Langmuir isotherm.With the Xenon lamp as the light source,under the optimal degradation conditions,the removal rate of AR3R reaches 100%after 30 min photocatalytic reaction.The capture agent experiments show that the·O₂ played a major role in the reaction system.Fe₃O₄@Sn-MOF has high stability.After 7 times of reuse,the removal rate of AR3R is still above 90%,and the structure didn't change significantly.