Preparation Of Modified SnO₂ And Its Photocatalytic Performance

Water pollution is serious all over the world,and the amount of harmful wastewater discharged by industry is increasing.The dye wastewater discharged from the printing and dyeing and textile industries is the main component of my country’s industrial wastewater.The water environment will be polluted to a very deep degree by these textile wastewater,and it will also bring great harm to human health.Photocatalysis can efficiently degrade organic dyes with the help of light energy,and has low cost and is easy to operate.Therefore,it is widely used in the degradation of organic dye wastewater.Tin oxide（Sn O₂）is regarded as an excellent photocatalyst because of its low cost,easy manufacture,low toxicity and high thermal stability.However,because the band gap width of tin oxide material is relatively wide,the electrons generated after being excited by light and the holes inside the material are easier to recombine,and the energy that can be absorbed by light with a wavelength greater than 420nanometers is very low,so It limits the research on the photocatalytic performance of tin oxide under visible light conditions.Therefore,by modifying the tin oxide material,the composite material can reduce the band gap,suppress the electrons generated after being excited by light and the holes in the material,and it is easier to recombine.The energy that light can absorb to achieve the purpose of increasing the degradation rate of the tin oxide material participating in the photocatalytic degradation of rhodamine B solution(10mg·L^-1)under the condition of simulating visible light.（1）In this paper,a new type of magnetic recyclable tin oxide/magnetic nano-onion carbon（Sn O₂/MCNOs）composite material was prepared by a simple hydrothermal synthesis method.X-ray diffraction test（XRD）,X-ray photoelectron spectroscopy（XPS）,scanning electron microscope（SEM）,specific surface area test（BET）,hysteresis loop test（VSM）,ultraviolet-visible diffuse reflectance test（UV-vis DRS）,Fourier Infrared Spectroscopy（FT-IR）and electrochemical tests to characterize the crystal structure,elements,microscopic morphology,pore size distribution and specific surface area,magnetic properties,light absorption properties,functional groups and photoelectric properties of the material,Confirmed the successful preparation of the material,paramagnetism,the enhancement of visible light response,and the improvement of photoelectric performance.The results of the study show that the superconductivity of the magnetic nano-onion carbon inhibits the recombination of electron-hole pairs,and the heterojunction formed by the combination of tin oxide and the magnetic nano-onion carbon improves the electron mobility and makes the optical properties of the composite more consistent.Compared with Sn O₂ monomer,there is a significant improvement.Under simulated sunlight,add 0.5g·L^-1 of a compound containing 4%MCNOs in a 10mg·L^-1 rhodamine B solution,the photocatalytic degradation rate can reach96%,and the cycle of the composite material is stable Sex is also very good.Free radical trapping experiments show that during the photocatalytic degradation of Rhodamine B by Sn O₂/MCNOs,the free radicals participating in the reaction include holes,superoxide free radicals and hydroxyl free radicals,among which the free radicals that have the most influence on the photocatalytic degradation process are free radicals.Holes.（2）In this paper,using the hydrothermal synthesis method and heat shrinking method,the tin oxide/reticulated carbon（Sn O₂/RCs）composite material was successfully prepared.X-ray diffraction test（XRD）,X-ray photoelectron spectroscopy（XPS）),scanning electron microscope（SEM）,specific surface area test（BET）,ultraviolet visible diffuse reflectance test（UV-vis DRS）,Fourier infrared spectroscopy test（FT-IR）and electrochemical test on the crystal structure and elements of the material,The microscopic morphology,pore size distribution and specific surface area,light absorption performance,functional groups and photoelectric properties were characterized,and the successful preparation of the material,the enhancement of visible light response,and the improvement of photoelectric properties were confirmed.The research results show that the specific surface area and pore structure of the material are increased due to the introduction of reticulated carbon,and the heterojunction formed by the combination of tin oxide and reticulated carbon improves the electron transfer ability and makes the optical properties of the composite comparable to Sn O₂ monomer.The ratio is significantly improved.Under simulated sunlight,add 0.5g·L^-1 of a compound containing 3%RCs in a 10mg·L^-1 Rhodamine B solution,the photocatalytic degradation rate can reach 93%,and the cycle of the composite material is stable Sex is also very good.Free radical capture experiments show that in the process of Sn O₂/RCs photocatalytic degradation of Rhodamine B,the free radicals participating in the reaction include holes,superoxide radicals and hydroxyl radicals,of which the free radicals have the most influence on the photocatalytic degradation process.Holes,slightly more affected are superoxide radicals.