Study On The Photocatalytic Performance Of G-C₃N₄ Nanotube Composites

As an important conjugated polymer,graphite carbonitride?g-C₃N₄?is an important research object in the field of photocatalysis.Its properties that do not contain metal elements and its responsiveness in the visible light band are The field of energy conversion and environmental restoration has caused widespread concern.This is attributed to the material's advantages of proper energy band structure,strong chemical and physical stability,and low cost of raw materials required for preparation.However,the wide band gap of g-C₃N₄ makes its application in the visible range still relatively large.In this paper,the construction method of giving tube-shaped morphology and semiconductor heterojunction was successfully used to prepare g-C₃N₄ tube and its derivative materials,which effectively extended the photocatalytic photoresponse range of g-C₃N₄ based composite materials from ultraviolet to visible light area.Compared with bulk g-C₃N₄,g-C₃N₄ based composite materials have better photocatalytic degradation of pollutants,photocatalytic sterilization and photoreduction of chromium ions in the visible light range.The detailed work is as follows:1.The g-C₃N₄ nanotubes were synthesized using solid-phase heat treatment,and the structure and performance of g-C₃N₄ nanotubes were verified through a series of material characterization techniques.Combined with an electron microscope,the size range of g-C₃N₄ nanotubes is clearly observed between 20-200 nm.The data obtained provide a basis for the next step in the precise control of the length of g-C₃N₄ nanotubes during the preparation process.Compared with g-C₃N₄ nanosheets,the tubular morphology brings a unique one-dimensional direction of photogenerated electron transport,which can provide more active sites for catalytic reactions in the actual catalytic system,effectively improving g-C₃N₄ photocatalysis.effectiveness.2.The hydrothermal method was used to combine g-C₃N₄ nanotubes with copper sulfide in one step,and copper sulfide/graphite carbon nitride nanotubes?Cu S/CN NTs?were prepared,And by adjusting the amount of g-C3N4?nanotube input to obtain three samples of different proportions.TEM and SEM accurately measured the length of Cu S/CN NTs is the same as g-C₃N₄ nanotubes in?1?.Cu S is evenly and finely distributed on the wall of the graphite phase nitrogen g-C₃N₄ nanotubes.The UV-Vis absorption spectrum characterization confirmed that at 300-800 nm the composite material has excellent response ability.Combined with photoluminescence spectroscopy,it is shown that the addition of Cu S component promotes the separation efficiency of photogenerated electron-hole pairs.Among them,the Cu S/CN NTs-2 sample had a killing rate of 99.9%for 1×10⁷ CFU/m L E.coli and Staphylococcus aureus when exposed to light for 150 min.3.On the basis of?2?composite materials,a further optimization was carried out,the introduction of cuprous sulfide,the synthesis of cuprous sulfide/copper sulfide/graphite phase carbon nitride nanotube ternary composite materials?Cu₂S/Cu S/CN NTs?,And by adjusting the amount of g-C3N4?nanotube input to obtain three samples of different proportions.The newly introduced components of nano-copper sulfide and cuprous sulfide in the composite material further enhance the visible light response of the composite material.Through the photocatalytic reduction experiment of hexavalent chromium ions under visible light,after 180 min of visible light irradiation The degradation rate of Cr???by Cu₂S/Cu S/CN NTs-2 is 96%,which is 4.3 times that of g-C₃N₄nanotubes.Confirmed that it has excellent photocatalytic performance.