Study On The Preparation Of Fe-based Metal Composites Based On Supramolecular Template Structure And Their Photocatalytic Properties

In recent years,photocatalytic technology has become one of the most promising ways to solve the current environmental and energy problems because of its efficiency,cleanliness and abundant of solar energy.Therefore,researchers focus on the development of more efficient and environmentally friendly photocatalysts as one of the main research topics.Among them,iron-based and iron-based composite materials have become one of the most popular photocatalytic materials due to their abundant raw materials,suitable band gaps,and stable physicochemical properties.However,iron-based materials also have the disadvantages of low specific surface area,few reactive sites,and low separation efficiency of photogenerated electron-hole pairs,which hinders the further application of iron-based materials.Therefore,we hope to synthesize iron-based materials with special morphology by simple and effective methods,and compound them with other materials to increase the specific surface area,active sites,and improve the separation efficiency of their photogenerated electron-hole pairs to further improve the photocatalytic performance.（1）The triazole ring group was introduced into the carbon nitride framework by supramolecular self-assembly and subsequent pyrolysis.A three-dimensional（3D）tubular carbon nitride is prepared,which not only has a large comparative area,but also has excellent separation ability of photogenerated electron-hole pairs.Then,we synthesized nano-sizedα-Fe₂O₃ particles by a simple hydrothermal method.Subsequently,combined theα-Fe₂O₃ nanoparticles with 3D tubular carbon nitride by electrostatic adsorption.The synthesized composite material not only has better light absorption ability in the visible light range,but also has a large specific surface area and many active sites.More importantly,a Z-scheme heterostructure is formed between theα-Fe₂O₃ nanoparticles and the 3D tubular carbon nitride,which further enhances the photogenerated carrier separation efficiency of the composite material.Therefore,in the case of pure water without using a sacrificial reagent,the catalyst can still exhibit excellent hydrogen production performance of photocatalytic splitting water.（2）Using molecular self-assembly,iron ions were anchored in the supramolecular structure,and the supramolecular structure was used as a soft template to prepare a loofah sponge-likeα-Fe₂O₃@C composite structure.Because of its special morphology,it has a large specific surface area.Meanwhile,the existence of the carbon layer not only enhances the stability of the material,but also improves the separation efficiency of photogenerated electron-hole pairs.When the material is used in the degradation of nitrobenzene reaction system,which shows excellent ability to degrade pollutants.Through mechanism experiments,we find that the excellent performance is due to the synergistic reaction of photocatalysis and photo-Fenton,and the process of the synergistic reaction and the entire degradation route of the degraded substance are deduced based on the experimental data,indicating that the degradation intermediate is nontoxic Non-polluting.（3）By supermolecular template method,iron and nickel ionsl bimetals were anchored in the HOF structure,and then a 3D loofah-like Ni Fe₂O₄@C is prepared by calcination.Taking the catalytic degradation of tetracycline by photocatalysis and photo-Fenton as an example,the effects of different calcination temperatures,different amounts of H₂O₂and different p H values on the degradation rate were studied.we found that Ni Fe₂O₄@C can exhibit excellent nitrobenzene degradation efficiency in a wide p H range（3-11）.And through a series of analysis and characterization,it can be obtained that the presence of bimetals increases the number of reactive sites and promotes the efficient use of H₂O₂.It is clear that the main active species of the reaction are·OH,h⁺,and O^2-.A variety of active substances act together on the pollutants,indicating that photocatalytic and photo-Fenton synergistic reactions have excellent ability to degrade pollutants.