Preparation Of Novel Photocatalytic Materials And Their Performance Study In Degrading Antibiotics And Removing Cr⁶⁺

The large-scale production and use of antibiotics will inevitably cause environmental pollution and pose potential harm to human health and ecological health.Faced with the increasingly severe problem of environmental pollution,it has become urgent to take effective measures to eliminate pollutants.However,pollutant degradation technology is not satisfactory in degradation efficiency and harmless treatment,so the development of efficient and green treatment technology has become a research hotspot.Under normal circumstances,photocatalytic materials with narrow spectral response range（such as titanium dioxide）generally have the disadvantage of low separation efficiency of photogenerated carrier,which seriously restricts the development of their technology.However,photocatalytic degradation of pollutants is a green technology with relatively potential to deal with environmental pollutants.Based on the above discussion,a photocatalyst construction method based on surface plasmon resonance effect and S-scheme heterojunction characteristics is proposed in this paper,so as to improve the light absorption capacity of photocatalytic materials and further improve the photocatalytic degradation performance of environmental pollutants.A novel Ag/Ag₂CO₃/Bi VO₄plasmonic photocatalyst was successfully prepared by depositing Ag nanoparticles on the surface of Ag₂CO₃/Bi VO₄through the photoreduction reaction.Due to the existence of this novel heterojunction photocatalyst structure,not only can it prevent the photogenerated charge recombination,but the unique properties of Ag also have a great advantage in the absorption of light.The Ag/Ag₂CO₃/Bi VO₄photocatalyst showed good catalytic performance in the degradation of oxytetracycline hydrochloride（OTH）and removal of Cr⁶⁺,and the degradation rate of OTH reached 98.0%after 150 min of illumination.The successful preparation of Ag/Ag₂CO₃/Bi VO₄was confifirmed by a series of characterization methods,and the importance of·OH and h⁺radicals in the degradation of OTH was demonstrated.In addition,the photocatalytic mechanism of Ag/Ag₂CO₃/Bi VO₄photocatalyst was systematically studied in terms of degradation of OTH and reduction of Cr⁶⁺.A novel efficient Cu₂WS₄/Mo S₂step-scheme（S-scheme）heterojunction photocatalyst was constructed for the first time and applied in the removal of environmental pollutants.In all the prepared photocatalysts,the Cu₂WS₄/Mo S₂-8%heterojunction photocatalyst shows the highest catalytic activity,the photocatalytic reduction efficiency of Cr⁶⁺and the photocatalytic oxidation efficiency of tetracycline（TC）can reach 82.1 and 93.3%,respectively.The Cu₂WS₄/Mo S₂heterojunction photocatalysts are characterized by satisfactory stability and excellent photocatalytic properties,which are attributed to the effective separation of charges and the formation of S-scheme heterojunctions,together with stronger redox capabilities.In addition,after in-depth analysis of the experiments and theoretical calculations,it is speculated that the Cu₂WS₄/Mo S₂heterojunction photocatalyst follows a typical S-scheme photogenerated carrier transferring mechanism,which is verified by the experimental results including the free radical quenching experiments,electron paramagnetic resonance（EPR）analysis,as well as the simulated calculations,such as the charge density distribution,built-in electric field,and energy band deflection.The built-in electric field and band offset act as driving forces for photoinduced electron and hole separation,ensuring that the Cu₂WS₄/Mo S₂S-scheme heterojunction photocatalysts maintain superior photocatalytic oxidation and photocatalytic reduction activities.Finally,the photocatalytic mechanism of S-scheme photogenerated carrier migration for the Cu₂WS₄/Mo S₂heterojunction photocatalyst is proposed based on the experimental and simulated results.This paper is of great significance for the development of new plasma heterojunction photocatalysts and S-scheme photocatalytic systems and for meeting future environmental requirements.