Synthesise Of The MIL-53(Fe)-Based Hybrid Photocatalyst And Their Degradation Performances Of The Organic Pollutants

Semiconductor photocatalytic technology is an advanced oxidation process,which has the advantages of non-toxicity,safety and radical oxidation.Among many wastewater treatment technologies,photocatalytic oxidation technology has attracted wide attention of domestic and international researchers on account of its unique superiority in the field of wastewater treatment and environmental treatment.At present,Titanium dioxide,on behalf of the traditional semiconductor materials still have many problems which are difficult to solve because of its shortcomings of the low quantum yield,easy inactivation,narrow optical absorption range and so on,limiting its application in the field of photocatalytic degradation.Hence,the exploitation of new type of photocatalytic materials has become a research hotspot in the forefront of the discipline.MIL-53?Fe?is a three-dimensional porous organic framework.Its band gap is roughly 2.7eV,which could absorb visible light.Nevertheless,its photocatalytic degradation performance is poor.Therefore,the study of new type of MIL-53?Fe?composite photocatalyst is of great significance.BiOCl is a kind of bismuth salt with alternating internal structure of[Bi₂O₂]²⁺and Cl^-bilayer.The lattice defects will be caused in the synthesis of BiOCl with using ethylene glycol as solvent and its photocatalytic degradation performance will be improved.At the same time,MoS₂and g-C₃N₄ also show great photocatalytic degradation potential.In this paper,MIL-53?Fe?was compounded with BiOCl and MoS₂ respectively.And MIL-53?Fe?was calcined at high temperature which was deposited to the surface of g-C₃N₄.Three new photocatalytic materials were successfully prepared.The crystal form,surface structure and morphology of the materials were characterized by scanning electron microscopy?SEM?,transmission electron microscopy?TEM?,X-ray diffraction?XRD?and Fourier transform infrared spectroscopy?FTIR?.Visible diffuse reflectance spectroscopy?UV-Vis DRS?,fluorescence spectroscopy?PL?,photocurrent?PC?and electrochemical impedance spectroscopy?EIS?were used to investigate the photochemical properties of the materials.In the meanwhile,2,4-dichlorophenol?2,4-DCP?,Rhodamine B?RhB?and tetracycline hydrochloride?TC-HCl?were selected as three model pollutants.The photocatalytic degradation performance of the materials was investigated by photocatalytic technology and the catalytic mechanism was discussed.The following conclusions were drawn from the study:The results showed that:?1?MIL-53?Fe?/BiOCl photocatalyst was prepared by two-step solvothermal method and 2,4-DCP was degraded under visible light.Optimum ratio was selected to test the photo-Fenton performance.Within 150minutes,the removal rate of 20 mg/L 2,4-DCP could reach up to100%.?2?Mo S₂/MIL-53?Fe?,as a visible-light photocatalyst,was prepared by in-situ synthesi s.RhB was decomposed under visible-light irradiation,and the removal rateof15mg/L RhB was 99%within 180 minutes.?3?Fe₂O₃/g-C₃N₄ visible-light phot ocatalyst was prepared by one-step calcination method to degraded TC-HCl und er photo-Fenton condition.And removal rate of 50 mg/L TC-HCl could reach up to 95%within 180 minutes under visible-light.The innovations of this paper:?1?Three kinds of visible-light photocatalyti c materials that are MIL-53?Fe?/BiOCl,MoS₂/MIL-53?Fe?and Fe₂O₃/g-C₃N₄ hav e been successfully prepared for the first time.The three photocatalysts have e xcellent photodegradation effects on 2,4-DCP,RhB and TC-HCl,respectively.?2?MIL-53?Fe?/BiOCl and Fe₂O₃/g-C₃N₄ have excellent photo-Fenton properties,s howing good degradation performance on high concentration organic simulated wastewater.?3?MoS₂/MIL-53?Fe?exhibits high adsorption and photocatalytic de gradation activity for RhB under visible light irradiation.The study of three ki nds of photocatalytic materials provides a new idea for the treatment of waste water by photocatalytic oxidation process.