| Metal-organic frameworks(MOFs) are bridged by inorganic metal ions(or metal clusters)and organic ligands,and are connected to each other through self-assembly to form a class of crystalline materials with periodic topological structures.Because of its large specific surface area,uniform pore size distribution,and many catalytic active sites,it has become one of the research hotspots in the field of new crystalline materials,and it has received extensive attention from many researchers in the photocatalytic degradation of organic pollutants in water.In this paper,the ligand 4-(2-nitro-4-carboxyphenyl)isophthalic acid(H3L)and transition metal Cu and the auxiliary ligand 1,2-bis(4-pyridyl)ethane(bpa),2,2'-bipyridine(2,2'-bipy),synthesized three copper(II)metal organic framework compounds{[Cu(HL)(2,2'-bipy)?(H2O)]?(H2O)}n(1),[Cu(HL)(2,2'-bipy)]n(2),[Cu(HL)(bpa)]n(3).The ligand 3,5-bis(3,4-dicarboxyphenoxy)benzoic acid(H5L)and the transition metal copper,cobalt,zinc and the auxiliary ligand 4,4'-bipyridine(4,4'-bipy),2,2'-bipyridine(2,2'-bipy)synthesized four metal organic framework compounds[Cu L(CH3CN)?(H2O)]n(4),[Cu L(2,2'-bipy)]n(5),[Co2L(H2O)7]n(6),[Zn2L(H2O)]n(7).The seven MOFs were characterized by X-ray single crystal diffraction analysis(XRD),X-ray powder diffraction analysis(PXRD),infrared spectroscopy(FT-IR),and thermogravimetric analysis(TGA).Taking the organic dye methyl orange(MO)as the target pollutant,the photocatalytic degradation experiments of complexes 1?3 were carried out,and the photocatalytic activity of complexes 1?3 as photocatalysts for the degradation of methyl orange was investigated.Taking tetracycline hydrochloride(TC-HCl)as the target pollutant,the photocatalytic degradation experiments of complexes 4?7 were carried out,and the photocatalytic activity of complexes 4?7 as photocatalysts for the degradation of tetracycline hydrochloride was investigated.And on this basis,the reaction mechanism of photocatalytic degradation was explored.The results show that the addition of H2O2 can greatly improve the photocatalytic degradation effect of complex 1 on methyl orange,and the photocatalytic degradation effect of complex 4 on tetracycline hydrochloride is better,but other synthesized complexes have better effects on methyl orange and tetracycline hydrochloride.The degradation effect is not good.Capture experiments show that h+and·O2-play a major role in the degradation of methyl orange by complex 1 under visible light,and·OH and·O2-play a major role in the photocatalytic decomposition of tetracycline hydrochloride by complex 4.In addition,the photocatalytic activity of complexes 1 and 4 did not decrease significantly after several consecutive cycles,indicating that complexes 1 and 4 have higher stability. |
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