Preparation of Fullerene Supported Iron Nano Catalyst Materials and Photo-fenton Degradation of Pollutants under Visible Light

Author:Zou Cong Yang

Supervisor:shen zhe min

Database:Doctor

Degree Year:2018

Download:50

Pages:147

Size:6860K

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Photocatalysis and Fenton oxidation methods are two commonly technologies.Preparing high quantum efficiency photocatalytic materials with high light energy conversion efficiency,high quantum efficiency and easy to recycle and reuse is the mainstream for oxidation technology.These new materials can used for visible light heterogeneous Fenton system,and unite photocatalytic with Fenton method.It has a great theoretical significance and practical significance to study the photocatalytic/photo-Fenton system degradation probe pollutants under visible light radiation.Spinel ferrate and hematite(Fe2O3)have attracted much attention due to their narrow band gap of about 2.0EV,high photocorrosion resistance,easy separation,recycling and high catalytic activity.Fullerene C60,also known as soccer,is the third isoform of carbon in addition to diamond and graphite.Because of its unique three-dimensionalπ-electron delocalization structure,it has a strong ability to capture electrons and transfer electrons under light radiation.In this paper,the traditional photo Fenton system is improved,and the novel and efficient C60 composite ferrate(C60-MFexOy)heterogeneous visible Fenton Catalyst were prepared.we used fullerene to modified ferrite(MFexOy:M=Bi、Mn、Co、Cu),with different content of fullerene.In addition,Iron oxide(Fe2O3)was doped onto fullerene[60](C60)to form C60-Fe2O3 composite using an easy and scalable impregnation method.The as-prepared C60-MFexOy/Fe2O3 samples were characterised.The photocatalytic activity of these catalysts were evaluated by measuring the degradation of typical pollution under visible light(>420 nm)in the presence of hydrogen peroxide.We used active species trapping experiments to distinguish the main active oxidant in the photocatalytic reaction process.The main results were shown as followed:1.BiFeO3 and C60-BiFeO3 composite was prepared using an easy hydro-thermal method.The X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),Raman,Transmission electron microscopy(TEM),Vibrating sample magnetometer(VSM)and a variety of characterization techniques to C60-BiFeO3 composition,structure and characters etc,were used to characterize the prepared materials.From the XRD and Raman patterns,the cubic crystal structure of BiFeO3 was observed.The crystal structure of C60-BiFeO3and BiFeO3 are identicaL.The crystalline phase are siderite calderite.The results of UV-Vis suggest that the response of the photocatalyst doped with fullerene to visible light were enhanced,and has red shift.When increased the content of fullerene,the adsorption edge was increased form 525nm to 554nm The BET value increased from 19.82m2/g of pure BiFe2O4 to 34.86m2/g of C60-BiFeO3.We used 0.02g of catalyst with 0.1mol/L H2O2(pH is 6.02)to degraded MB(50mL,20mg/L)solution.When the content of fullerene is 4%,the degradation rate for MB solution of C60-BiFeO3 is 97.58%,which is more higher than pure BiFeO3.We also used visible light/C60-BiFeO3/H2O2 system to degraded diclofenac acid(DCF),the degradation rate is 98.58%.The C60-BiFeO3 Catalyst showed high photoCatalytic activity in a wide pH range of 3.18-11.25.To evaluate the reusability of the C60-BiFeO3composite,the Catalyst was collected and reused five times to degraded the MB solution.This results indicates that the catalyst has an excellent photocatalyst stability and a high potential application value.We utilized the fluorescent probe terephthalic acid(TA)to assess the·OH formation.We also carried out the active species trapping experiments to distinguish the main active oxidant in the photocatalytic reaction process.Isopropanol,disodium ethylenediamine tetraacetate(EDTA-2Na),and nitrogen gas were introduced as various reactive species scavengers for hydroxyl radicals(·OH),holes(hv)and superoxide anion radical(·O2-).We find the hydroxyl radicals plays a major role in the whole process.2.CoFe2O4 and C60-CoFe2O4 composite was prepared using an easy hydro-thermal method.The X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM)and UV-visible diffuse reflectance spectra(UV-Vis DRS)and a variety of characterization techniques were used to characterize the prepared materials.The optimum conditions of photo Fenton reaction were discussed by studying different reaction conditions.We also used visible light/C60-CoFe2O4/H2O2 system to degrade diclofenac acid(DCF).We find the hydroxyl radicals play a major role in the whole process.3.MnFe2O4 and C60-MnFe2O4 composite was prepared using an easy hydro-thermal method.The X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),Raman,Transmission electron microscopy(TEM),Vibrating sample magnetometer(VSM)and a variety of characterization techniques were used to characterize the prepared materials..The optimum conditions of photo Fenton reaction were discussed by studying different reaction conditions.We find the hydroxyl radicals play a major role in the whole process.4.CuFe2O4 and C60-CuFe2O4 composite was prepared using an easy hydro-thermal method.The X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),Raman,Transmission electron microscopy(TEM),Vibrating sample magnetometer(VSM)and a variety of characterization techniques were used to characterize the prepared materials..The optimum conditions of photo Fenton reaction were discussed by studying different reaction conditions.We find the hydroxyl radicals play a major role in the whole process.C60-CuFe2O4,also has excellent effect for ammonia degradation.we using the density function altheory(DFT)method report an electronic structure study of NH3 Adsorption on one typical Low index plane of the spinel-type CuFe2O4,the(100)surface.The results presented here provide an initial understanding of the catalysis mechanism of NH3 molecule over CuFe2O4 surface.5.Iron oxide(Fe2O3)was doped onto fullerene[60](C60)to form C60-Fe2O3 composite using an easy and scalable impregnation method.The as-prepared C60-Fe2O3 samples were characterised by powder X-ray diffraction,X-ray photoelectron spectroscopy analysis,scanning electron microscopy,high-resolution transmission electron microscopy,UV-vis absorption spectroscopy,Raman spectroscopy and Fourier transform infrared spectroscopy.We also used visible light/C60-Fe2O3/H2O2 system to degrade organic dye and phenol.We find the hydroxyl radicals play a major role in the whole process.6.The photocatalytic mechanism of C60-BiFeO3,C60-CoFe2O4,C60-MnFe2O4,C60-CuFe2O4 and C60-Fe2O3 were investigated.The effects of the four C60-MFexOy systems on MB degradation were compared.It was found that the degradation ability of the four systems was as follows:C60-CuFe2O4>C60-MnFe2O4>C60-BiFeO3>C60-CoFe2O4 under the similar reaction conditions.