Photo-fenton Performance Of 2D FeOCl-based Composites

With the development of industrialization,water pollution in the environment has become more and more serious,which has aroused the attention of various countries,leading people to improve the environment and put forward new demands.The photo-Fenton technology is highly efficient,environmental protection,economic and does not produce secondary pollution,which has become the object of everyone’s favor,and the most core is the photo-Fenton catalyst.Compared with traditional materials,semiconductor materials show strange characteristics in physical and chemical properties,which is due to the small size effect and surface effect of nanoparticles.Among many photo-Fenton catalysts,FeOCl is characterized by its unique two-dimensional layered stacking structure.It is an indirect narrow band gap semiconductor material（band gap,Eg=1.8 e V）,which has excellent photoelectric conversion and provides abundant electrons.In the environment of H₂O₂,the chemical state of iron ion itself can be transformed in cycles.Therefore,it has attracted wide attention of scholars from all walks of life.In this paper,FeOCl was prepared by a simple calcination method,and the morphology of FeOCl was regulated by the treatment of the state of raw materials and the adjustment of temperature before calcination.Three kinds of semiconductor materials,g-C₃N₄/FeOCl Z-type heterojunction and Co-doped FeOCl,were constructed.To improve the photo-Fenton performance of FeOCl.The crystal structure,morphology,chemical bond,and photoelectrochemical properties of the samples were characterized by XRD,SEM,TEM,EDS,TEM-mapping,XPS,FT-IR,UV-vis,PL,EIS and transient photocurrent response.The photo-Fenton degradation efficiency and stability of the catalyst were evaluated by photo-Fenton experiments,active species capture experiments and cyclic stability experiments,and the photo-Fenton mechanism was explored.The specific research contents are as follows:1.A simple calcination method was used to prepare the cubic phase FeOCl photo-Fenton catalyst with irregular rectangular bars stacked in layers,irregular sheets stacked in flowers and decaying wood by changing the state of raw materials before the reaction and the reaction temperature.The photo-Fenton properties of FeOCl were evaluated under acidic conditions.Under the xenon lamp irradiation,the rectangular FeOCl degraded 26.5%of Rh B,the flower-like FeOCl degraded 98.8%,and the decayed wood-like FeOCl degraded 96.8%.Microstructure affects the photo-Fenton properties of FeOCl semiconductor materials.2.Amorphous non-metallic polymer g-C₃N₄ was prepared by calcination of melamine at high temperature.Then,the mass ratio of g-C₃N₄ and FeCl₃·6H₂O was 1:15,1:20 and 1:25,and the recyclable g-C₃N₄/FeOCl composite photo-Fenton catalyst was prepared.g-C₃N₄ covered the surface of rectangular FeOCl like gauze,forming Z-type heterojunction.By UV-vis characterization,it was found that the band gap of the composite material was widened and the light response range was widened.EIS and transient photocurrent response tests show that the Z-heterojunction reduces the recombination rate of carrier.The photo-Fenton test showed that the photo-Fenton performance of g-C₃N₄/FeOCl-2 was excellent and the degradation rate still reached 80.1%after three cycles The cyclic stability of FeOCl was obviously improved.3.Fe_1-xCo_xOCl（x=0.03,0.06,0.09）nanometer powders were prepared by calcination.The XPS map showed that Feand Co were in Fe³⁺/Fe²⁺and Co³⁺/Co²⁺states XRD shows that doping does not change the morphology of FeOCl.It still in the cubic phase of FeOCl.The SEM showed that the morphology of the sample was composed of rough nanosheets.The UV-vis spectrum found that the band gap value of the sample decreased with the increase of doping concentration,and the PL spectrum found that the quenching phenomenon would occur with the increase of Co doping concentration.Therefore,Fe_1-xCo_xOCl has excellent photo-Fenton properties and can produce more active free radicals during the degradation process.