Research On Preparation And Properties Of Surface Modified Multi-walled Carbon Nanotubes Loaded Ferrite

Ferrite is a complex metal oxide.It has been applied in many fields,such as piezoelectricity,sensing,medicine,adsorption and catalysis.However,the ferrite prepared by traditional method has many disadvantages,such as large diameter,strong agglomeration effect and uneven structure.In view of the excellent physical and chemical properties of multi wall carbon nanotubes,cobalt ferrites/multi wall carbon nanotube composites(Co_xNi_1-xFe₂O₄/MWCNTs)have been successfully prepared by a convenient and environmentally friendly solvent thermal method.XRD,SEM,EDS,TEM,SAED,XP and Raman were used to characterize the crystal shape,structure and morphology of the composite.The adsorption process of heavy metal ion Cd²⁺and the photocatalytic degradation process of the eosin B?eosin B,short EB?were studied.The adsorption and photocatalytic properties of the composites were studied.The structure activity relationship of composites is discussed,which provides a theoretical basis for the practical application of the material in the field of water treatment.?1?Firstly,the modified multi wall carbon nanotube was modified by constant pressure acidification,and the optimum conditions for the modified multi wall carbon nanotube were explored by adjusting the different reaction parameters,such as reaction temperature and reaction time.The results show that the reaction temperature has great influence on the morphology and dispersion of modified multi walled carbon nanotubes.When the reaction temperature is 80 h with the time of 2 h,the multi walled carbon nanotubes have complete structure with good dispersion and no impurities on the surface.?2?Nanoscale Co_xNi_1-xFe₂O₄ was prepared by one step solvothermal method.By adjusting the different reaction parameters,such as the type and concentration of precipitator,the reaction temperature,the ratio of cobalt and nickel,and so on,the optimum preparation conditions of nanoscale Co_xNi_1-xFe₂O₄ were explored.The results showed that the type and temperature of the solvent had great influence on the morphology and composition of the material.With 50%glycol solvent method,the morphology of polycrystalline nano spherical Co_xNi_1-xFe₂O₄ with uniform particle size about 16 nm was prepared when the reaction time was 2 h at the reaction temperature of 180?and 6 mmol urea as precipitant.It is known by XRD that the addition of nickel does not cause the lattice change,and the Co_xNi_1-xFe₂O₄ is always a spinel structure with a surface composition of(Co²⁺_0.46Ni³⁺_0.19Fe³⁺_1.4)[Co²⁺_0.3Ni²⁺_0.43Co³⁺_0.36Fe³⁺_0.6]O₄.?3?Finally,the modified multi walled carbon nanotubes with different contents were introduced on the basis of the preparation of Co_xNi_1-x-x Fe₂O₄.It was characterized by SEM that the Co_xNi_1-xFe₂O₄ was uniformly loaded on the multi wall carbon nanotubes.The ID/IG was1.36 and 1.34 respectively,and the specific surface area of the composite was 157.27 m²/g,and the diameter distribution was concentrated.Between 2-10 nm.?4?In this paper,Co_xNi_1-x-x Fe₂O₄/MWCNTs as adsorbent material prepared by solvent thermal method,Cd²⁺as the research object,by controlling the initial concentration of pH,time,Cd²⁺,to explore the best adsorption conditions.The results show that when the solution pH is 8,the reaction time is 30 min,and the initial concentration of Cd²⁺is 400 mg/L,the maximum adsorption capacity is 60.02 mg/g.According to the kinetic equation,Co_xNi_1-xFe₂O₄/MWCNTs conforms to the quasi two level kinetic equation,indicating that the reaction is mainly chemical adsorption.According to the adsorption isotherm model,the linear correlation coefficient of Langmuir fitting is R² more than 0.9937,which indicates that the surface of the material is more uniform,and the adsorption process belongs to the chemical adsorption process based on the adsorption of single molecular layer.?5?In this paper,five kinds of composite materials synthesized by hydrothermal method were used as photocatalyst materials with the EB as the research object.The results show that when the ratio of cobalt and nickel is 0.3:1.0,the highest degradation rate of EB is 98.11%.After five cycles,the degradation rate of the five materials is still more than 97%with the good cycle stability.In this paper,the study on the adsorption and photocatalysis of cobalt ferrites/multi walled carbon nanotube composites with different components content provides a basic experimental method for the preparation of nanocomposites with excellent properties,and provides a good prospect for the application and development of adsorbents and photocatalytic materials.