Preparation Of Metal Organic Framework Composite Catalyst And Photocatalytic Degradation Of Bisphenol A

With the rapid development of industry,human daily life and production activities have caused extremely serious water pollution problems.Bisphenol A（BPA）is a very difficult pollutant to treat.It can interfere with the endocrine system of humans and animals.BPA in wastewater has become a topic of widespread concern to researchers.At present,there are various methods for treating BPA in the environment,including physical adsorption,microbial degradation,advanced oxidation process（AOP）,and photocatalysis.Among them,photocatalysis is considered to be a potential method to remove BPA due to its high efficiency and environmental protection.Metal-organic frameworks（MOFs）have become one of the most promising photocatalysts at present due to their variable and easily adjustable structures,their inherently porous nature,and their large specific surface area.However,most MOFs as photocatalysts can only obtain ultraviolet light and have a wide band gap,which greatly limits their further applications in the field of photocatalysis.It is a common method to enhance the photocatalytic performance of MOFs by compounding MOFs with other semiconductors.This method can effectively improve the utilization of sunlight and avoid the recombination of photo-generated electrons and holes.This paper designs and constructs two new MOFs-based composite photocatalysts,which provide new synthetic ideas and research methods for new materials for photocatalytic degradation of BPA.In this paper,a new type of anatase-type Ti O₂@MIL-101（Cr）composite was synthesized by solvothermal method.The prepared catalyst was characterized by XRD,SEM,BET,EDS,TEM,XPS to prove its chemical structure.The effects of the Ti O₂content,the initial p H value of the water environment,the amount of catalyst and the initial BPA concentration on the photodegradation activity were studied.Under optimized conditions,59%Ti O₂@MIL-101（Cr）can achieve 99.4%BPA degradation,and the corresponding rate constant（k）is 0.0138 min^-1.Three intermediate products of the degradation process were detected by HPLC-MS,and the photocatalytic degradation path of BPA was studied.The mechanism of photocatalytic degradation of BPA by Ti O₂@MIL-101（Cr）composite was proposed.A heterostructure of B-Ti O_2-x@ZIF-67 was constructed,and BPA was degraded under visible light to investigate the photocatalytic degradation performance.The composites were characterized by XRD,SEM,TEM,EDS,FT-IR and XPS,and the physical properties and chemical structure of the composites were confirmed.Addition of H₂O₂under visible light can reach a BPA degradation rate of 95.3%within 60 minutes,and the corresponding rate constant（k）is 0.046 min^-1.Electrochemical experiments,electron spin resonance spectroscopy and free radical shielding experiments were analyzed to propose a feasible photocatalytic mechanism.The excellent degradation efficiency is attributed to the constructed B-Ti O_2-x@ZIF-67 heterostructure with a suitable band position.Under visible light irradiation,it can successfully promote the activation of H₂O₂to generate hydroxyl radicals,and promote carriers.Effective transfer.This work provides a feasible method for the degradation of BPA in the environment.