Preparation Of Ag₃VO₄/Ag₂CO₃ P-n Heterojunction And Its Degradation Of Levofloxacin And Rhodamine B In Aqueous Solution

The rapid progress of the times,the rapid development of society,has achieved a high degree of industrialization today.However,while human beings continue to develop high-tech products,new medical supplies and products to meet the needs of human beings,the various pollutants produced have caused serious damage to our ecological environment,which has seriously affected the ecological balance of nature,the normal life of human beings and the growth and reproduction of organisms.Photocatalytic technology has unique advantages in the field of environmental purification due to its advantages of high efficiency,cleanliness and low energy consumption.At present,photocatalytic materials with visible light response have become a hot spot in the field of water purification.In the field of photocatalysis,the construction of a heterojunction system with efficient charge separation at the interface and charge transfer to increase the photocatalyst performance has gained considerable attention.In this study,the Ag₃VO₄/Ag₂CO₃ p-n heterojunction is first synthesized using a simple co-precipitation method.The composite photocatalyst with a p-n heterojunction has a strong internal electric field,and its strong driving force can effectively solve the problem of low separatio n and migration efficiency of photogenerated electron-hole pairs.The optimized Ag₃VO₄/Ag₂CO₃ composite can effectively degrade organic pollutants（levofloxacin（LVF）and rhodamine b（Rh B））.More specifically,the Ag₃VO₄/Ag₂CO₃ photocatalyst with a 1:2 mass ratio（VC-12）can remove 97.8%and82%of Rh B and LVF within 30 and 60 min,respectively.The LVF degradation rate by VC-12 under visible light irradiation is more than 12.8 and 21.51 times higher than those of pure Ag3VO4 and Ag2CO3,respectively.The e xcellent photocatalytic activity of the Ag₃VO₄/Ag₂CO₃ hybrid system is mainly attributed to the internal electric field that forms in the Ag₃VO₄/Ag₂CO₃ p-n heterojunction system,the photogenerated electron hole pairs that separate and facilely migrate,and the specific surface area of VC-12 that is larger than that of the monomer.In addition,the degradation efficiency of VC-12 did not decline significantly after four cycles.In this study,the photocatalytic mechanism for Ag₃VO₄/Ag₂CO₃ photocatalysts is explored in detail based on the energy band analysis results,trapping experiment results,and electron spin resonance spectra.Finally,the LVF degradation products are analyzed by liquid chromatography-mass spectrometry,and the potential LVF degradatio n pathway is identified.The experiments performed in this research therefore lead to new motivation for the design and synthesis of highly efficient and widely applicable photocatalysts for environmental purification.