Study On Modification Of Bismuth Oxychloride And Its Degradation Performance Of Ciprofloxacin

The abuse of antibiotics has become an important part of environmental pollution,and it is an emerging issue that has attracted worldwide attention.Take Ciprofloxacin（CIP）,one of the most difficult-to-degrade fluoroquinolone drugs,for example.Although it is effective against infectious diseases,it has been detected in surface water,groundwater,wastewater,and even drinking water in recent years.,And its concentration tends to increase.Residues of antibiotics in the aquatic environment will have a negative impact on the microbial population structure and metabolic genetics,and may even produce resistance genes.This will pose a great threat to the healthy development of human bodies.However,the traditional physical,biological,chemical and other wastewater treatment technologies are not ideal for the treatment of ciprofloxacin.The photocatalytic treatment technology has attracted more and more people’s attention because of its high efficiency,low cost,and environmental protection.In recent years,bismuth oxyhalides（BiOCl,BiOBr,BiOI）have received extensive attention from researchers because of their simple preparation process,stable chemical properties,and higher photocatalytic activity than commercial P25.Among them,bismuth oxychloride is more popular because of its brighter color than the other two catalysts,a wide range of materials,and good visible light photocatalytic activity.However,bismuth oxychloride has a weak ability to absorb visible light,which is limited in practical applications.In this paper,a simple hydrolysis method was used to prepare pure phase bismuth oxychloride with good catalytic performance.The bismuth oxychloride was modified by introducing metal oxides and carbon matrix materials to form a BiOX/BiOY two-phase composite photocatalyst.,In order to broaden the material’s light absorption range and photoelectric performance and other properties,in order to enhance the material’s degradation effect on ciprofloxacin,so that it can treat pharmaceutical wastewater more efficiently.（1）The addition of CuO nanoparticles can significantly enhance the adsorption performance,degradation performance,visible light response ability and interface charge transfer ability of BiOCl semiconductor.The recombination of electron-hole pairs of the material is obviously suppressed,and the maximum absorption edge in response to visible light is increased from351nm to 435nm.Especially 4-CuO/BiOCl has a saturated adsorption rate of 53.07%for ciprofloxacin.Under visible light irradiation,the removal rate of ciprofloxacin reaches 93.15%after 60 minutes,and its kinetic constant is that of pure BiOCl.6.2 times,the catalytic effect is significantly improved.After five times of recycling,the material showed good stability and degradability.Studies on the photocatalytic mechanism show that the main free radical species for photocatalytic degradation of CIP is·O₂-.（2）After the carbon ball and the bismuth oxychloride compound,the photoresponse and adsorption capacity of the material are increased,and the photocatalytic effect is significantly enhanced.Compared with the traditional photocatalytic material,titanium dioxide,it has higher catalytic activity.In addition,the composite material has good stability and still has strong photocatalytic performance after being recycled for 5 times.（3）BiOX/BiOY two-phase composite photocatalyst is composed of bismuth oxychloride and other two bismuth oxyhalide materials,which increases the photoresponse ability of the material and significantly enhances its photocatalytic effect.Compared with traditional photocatalytic material titanium dioxide Have higher catalytic activity.