Preparation And Optical Properties Of Metal Organic Framework Compound/rare Earth Doped Composite Materials

Rare earth up-conversion luminescent material with narrow emission band,strong light stability and long luminescence life has the advantages of low toxicity,high biocompatibility and high stability.At the same time,its excitation light will not cause damage to biological tissues,so up-converting luminescent materials have been regarded as the most promising new generation of biological fluorescence detection materials.However,it still has large size,uneven particle size,poor water solubility,low up-conversion fluorescence intensity,etc.Therefore,new requirements are placed on the morphology,characteristics,and fluorescence properties of up-conversion nanoparticles.The metal-organic framework has rich ligands and diverse structures.At the same time,it can also be used as an energy platform.It is expected to modulate the fluorescent properties of UCNPs by constructing composite materials.Similarly,rare earth luminescent materials with rich optical properties can also be combined with metal-organic frameworks to achieve a strong combination.This strategy is expected to broaden the application field and applicable situation of rare earth luminescent materials.In this paper,the following work is carried out for the purpose of regulating the fluorescent properties of rare earth luminescent materials,constructing composite materials,and exploring the energy conversion process:?1?The NaGd F₄:Yb,Er up-conversion nanorods with uniform morphology and good dispersion were prepared by hydrothermal method,and the reaction temperature,reaction time and reactant ratio were explored by changing the reaction conditions controlled the nanorods morphology,crystal,growth process and fluorescence performance.And the optimal reaction conditions for the preparation of NaGdF₄:Yb,Er up-conversion nanorods were obtained.When the NaGdF₄:Yb,Er up-conversion nanorods prepared at 180?for 18 h and Gd:NaF=1:6,the crystal were converted into pure?-type hexagonal phase with uniform morphology and good dispersion,and showing the best up-conversion fluorescence performance.?2?The NaGd F₄:Yb,Er up-conversion nanorods of the oil phase system were modified by a stepwise synthesis method.The metal organic framework ZIF-67 was introduced as an energy transfer platform,and construct the heterostructure ZIF-67/NaGdF₄:Yb,Er composite material.The heterostructure ZIF-67/NaGdF₄:Yb,Er composite material overcomes the shortcomings of NaGdF₄:Yb,Er nanorods that are easy to agglomerate and quench,and shows good stability.At the same time,the heterostructure ZIF-67/NaGdF₄:Yb,Er composite material breaks through the limitation of the oil phase system and shows good compatibility with alcohol.Compared with each component,due to the synergy between the two components,a controllable fluorescence tuning is realized.In addition,when the amount is 30%of NaGdF₄:Yb,Er upconversion nanorods were added,the heterostructure ZIF-67/NaGdF₄:Yb,Er composite material had the best fluorescence intensity,and the mechanism of its fluorescence transfer was explored.?3?By combining the metal organic framework with the rare earth complex luminescent material,the effect of the metal organic framework on the fluorescence performance of the rare earth complex luminescent material was explored.The metal-organic framework/rare earth complex composite material exhibits strong absorption and fluorescence quenching,so it cannot effectively improve the luminescence performance of the rare earth complex.However,this strategy is expected to broaden the application of rare earth luminescent materials in the fields of photocatalysis and photodegradation due to the adsorption of metal-organic frameworks.