Metal Organic Frameworks For Degradation And Identification Of Contaminants In Water

Metal-organic frameworks(MOFs)are constructed from the self-assembly of metal ions/clusters and organic ligands through coordination bonding resulting in 1-D,2-D,or 3-D network structure.Due to its structural flexibility,multiple metallic active sites,high surface area and porosity,MOF is suitable for the detection of pollutants in water through selective adsorption or catalytic degradation.Based on these,we have done the following work:1.MOF-199 material was synthesized by hydrothermal method,and the simultaneous detection of Cr(VI)and o-phenylenediamine(OPD)was realized in the same catalyst system.At the same time,in the presence of MOF-199 and Cr(VI),the three phenylenediamine isomers were transformed into colored compounds respectively to realize the qualitative identification of phenylenediamine isomers.Through the reaction,Cr(VI)was reduced to Cr(III)with less toxic and less soluble,realizing the degradation of Cr(VI).The limit of detection(LOD)of Cr(VI)and OPD were 0.1 and 0.52?M,respectively(LOD=3?/s,n=10).2.MOF-199-H₂O₂ system was constructed for the identification and detection of aminophenol isomers.In this system,the three aminophenol isomers are oxidized and polymerized to form different color,which can visually distinguish the aminophenol isomers.Simultaneously,the quantitative analysis methods of o-aminophenol(OAP)and p-aminophenol(PAP)were established.The limit of detection(LOD)of OAP and PAP were 0.188 and 0.704??,respectively(LOD=3?/s,n=10).Moreover,a smart phone colorimetric platform was constructed to analyze OAP and PAP by using the linear relationship between the RGB values output by the smartphone application and the concentrations of OAP(15-150?M)and PAP(15-240?M).3.MOF-199/ZIF-8 and MOF-199/ZIF-8@Fe₃O₄(the molar ratios are 5:0.5,5:1and 5:1.5 respectively)were prepared for quantitative analysis of aniline compounds OAP,PAP and OPD.The LOD of OAP,PAP and OPD were 0.176,0.556 and 0.464?M respectively.The use of external magnetic field for separation avoids complex operations such as centrifugation and can be reused for at least 7 times.