Preparation Of Bi₁₂O₁₅Cl₆ Based Composites And Their Photocatalytic Degradation Of Environmental Pollutants And Antibacterial Properties

In the process of social development,a large number of industrial practices and anthropogenic activities have caused environmental pollution.The current priority is to find suitable technologies to solve environmental and ecological problems.Semiconductor photocatalysis is an efficient method of converting light energy into chemical energy,which can be effectively used to degrade various organic pollutants.The practical application of single photocatalysts is limited due to their high photogenerated electron-hole complexation rate and low photocatalytic degradation performance.For this reason,researchers often use doping,surface modification and construction of heterojunctions to enhance the photocatalytic performance of photocatalysts.To enhance the photocatalytic degradation of organic pollutants and antibacterial properties of Bi₁₂O₁₅Cl₆,three kinds of Z-type heterojunction materials were synthesized by combining Bi₁₂O₁₅Cl₆ with various semiconductors to construct heterojunction structures,such as Bi₁₂O₁₅Cl₆/Sn O_2-x,Bi₁₂O₁₅Cl₆/In VO₄ and r GO/Bi₁₂O₁₅Cl₆/In VO₄.The prepared composites can possess high efficiency of photo-induced charge transfer and excellent photocatalytic degradation and antibacterial properties.The details of the study are as follows:（1）First,Sn O_2-x and Bi OCl/Sn O_2-x were prepared by hydrothermal method,and then Bi₁₂O₁₅Cl₆/Sn O_2-x composite was obtained by calcination of Bi OCl/Sn O_2-x.The crystal structure and morphological characteristics of Bi₁₂O₁₅Cl₆/Sn O_2-x were analyzed using XRD,HRTEM,TEM and other characterization methods to confirm that Bi₁₂O₁₅Cl₆/Sn O_2-x composite was successfully prepared.The results of XPS and ESR analysis indicated the presence of oxygen vacancies in the Bi₁₂O₁₅Cl₆/Sn O_2-x composite.The best sample of 30%Bi₁₂O₁₅Cl₆/Sn O_2-xdegraded 86.7%TC within 90 min and 99.7%Rh B within 75 min under LED light.Photocurrent and electrochemical impedance spectroscopy（EIS）confirmed that the Bi₁₂O₁₅Cl₆/Sn O_2-x material has efficient photoinduced charge transfer and separation efficiency.The results of energy band structure and trapping experiments suggest that the system follows a Z-type mechanism.（2）First,In VO₄ and Bi OCl/In VO₄ were prepared by hydrothermal method,and then Bi₁₂O₁₅Cl₆/In VO₄ composite was obtained by calcination of Bi OCl/In VO₄.XRD,XPS,TEM and SEM characterization results confirmed that the Bi₁₂O₁₅Cl₆/In VO₄composite was successfully prepared.The best sample of 30%Bi₁₂O₁₅Cl₆/In VO₄material can effectively degrade 78.85%of TC and 97.83%of Rh B within 90 min,and can inactivate 100%of S.aureus and E.coli in 40 min.Photocurrent and electrochemical impedance spectroscopy（EIS）confirmed better photogenerated carrier transfer and separation of Bi₁₂O₁₅Cl₆/In VO₄ composite.The results of energy band structure and trapping experiments suggest that the system follows a Z-type mechanism.（3）The r GO/Bi₁₂O₁₅Cl₆/In VO₄ composite was synthesized by introducing reduced graphene oxide（r GO）during the preparation of Bi₁₂O₁₅Cl₆/In VO₄ composite.XRD,XPS,TEM and SEM characterization results confirmed that the r GO/Bi₁₂O₁₅Cl₆/In VO₄composite was successfully prepared.The best sample 0.3%r GO/Bi₁₂O₁₅Cl₆/In VO₄degraded 99.1%of Rh B and 77.48%of TC in 75 min under LED light,and could inactivate S.aureus and E.coli in 30 min.Compared with binary Bi₁₂O₁₅Cl₆/In VO₄ and single photocatalyst,the r GO/Bi₁₂O₁₅Cl₆/In VO₄ ternary photocatalyst exhibited the best degradation and bacterial inhibition performance.Photocurrent and EIS confirmed that the introduction of r GO enhances the separation and migration efficiency of photogenerated carriers in Bi₁₂O₁₅Cl₆/In VO₄ composite.The results of energy band structure and trapping experiments suggest that the system follows a Z-type mechanism.