Synthesis And Properties Of MOFs With Polycarboxylic Acids

The identification and removal of harmful substances in water has always been one of the difficult problems.Metal-organic Framework（MOF）materials have been widely used in many fields such as identification,sensing and catalytic degradation due to their good performance.Based on this,different luminescence MOFs materials were designed and synthesized using polycarboxylic acid as ligands,and their structures and recognition performance were characterized and analyzed.Micron photocatalyst was prepared using Cd-MOF as precursor,and its catalytic degradation performance was tested and analyzed.The specific research contents are as follows:Synthesis,structure and fluorescence recognition of[Sr₃（bptc）_1.5（H₂O）_6.5]_n（1）.Complex 1 was synthesized by using 3,3’,5,5’-biphentetracarboxylic acid（H₄bptc）and Sr²⁺under hydrothermal condition.Single crystal X-ray diffraction shows that complex 1 belongs to hexagonal crystal system,P6₄22 space group.It exhibits a three-dimensional structure.Fluorescence test showed that the emission peak of complex 1 was the strongest at 370 nm.And it can recognize Fe³⁺and 4-nitrophenol（4-NP）very well.Its excellent performance is mainly attributed to the interaction between carboxyl oxygen atoms and analytes and the fluorescence overlap effect.Synthesis,structure and fluorescence recognition of[Cd（sip）（dpa）（H₂O）]_n（2）,[Cd（Hsip）（2adptIc）（H₂O）₂]_n（3）.Complex 2 was synthesized by using monosodium 5-sulfoisophthalate（NaH₂sip）,4,4’-dipyridinine（dpa）and Cd²⁺under hydrothermal condition.Complex 3 was synthesized by using monosodium 5-sulfoisophthalate（NaH₂sip）,2-acetylpyrazine isoniazide（2adpt Ic）and Cd²⁺through layered method.Single crystal X-ray diffraction shows that complex 2 belongs to triclinic crystal system,P-1 space group,and it contains one-dimensional chain.Complex 3 belongs to triclinic crystal system,P-1 space group,which manifesting a mononuclear structure.Fluorescence test showed that the emission peak of complex 2 was the strongest at 390 nm,and complex2 also recognized Fe³⁺and 4-NP well.Its excellent property is mainly attributed to the interaction between uncoordinated oxygen,nitrogen atoms and analytes and the fluorescence overlap effect.Preparation of catalysts and their catalytic degradation properties by using complex 2 and 3 as precursors.The photocatalysts Cd-S@500,Cd-S@600 and Cd-S@700 were obtained by calcination of complex 2 at 500℃,600℃and 700℃,respectively.The photocatalysts Cd-S-O@500,Cd-S-O@600 were obtained by calcination of complex 3 at 500℃and 600℃,respectively.Of which,Cd-S@600 is a rod-shaped micron particle.The photocatalytic degradation of Rhodamine B（RhB）by Cd-S@600 and Cd-S-O@600 was studied.The degradation rates of RhB reached 88%and 99%at 120 min,respectively.