Preparation And Photocatalytic Performance Of BiOiO₃ Compo Site Photocatalyst

Photocatalysis is a new pollution control method that has emerged in the last few years,with the characteristics of environmental protection,green and pollution-free.The key to photocatalytic technology is to find suitable semiconductor photocatalytic materials.Traditional semiconductor materials such as Ti O₂ have faded out of people’s field of vision due to their shortcomings such as insufficient visible light absorption.Therefore,the search for new semiconductor materials has become a new research hotspot.Bismuth-based photocatalysts show splendid photocatalytic capability in water environment remediation,and gradually play an important role in the field of semiconductor photocatalysts.However,its high electron-hole recombination rate,poor adsorption performance,and insufficient stability hinder its practical application in water treatment.Therefore,further modification on the basis of bismuth-based photocatalysts is needed to meet the practical application requirements.The structural layers of bismuth oxyiodate（BiOIO₃）are alternately staggered（Bi₂O₂）²⁺and（IO₃）^-,with a wide band gap and strong response under ultraviolet light,showing excellent catalytic performance under ultraviolet light,but under visible light.The insufficient response limits its utilization of sunlight.In order to widen the photoresponse range of bismuth oxyiodate and improve its low utilization rate of visible light,this study uses the method of semiconductor compounding to optimize its performance.The details are as follows:（1）Bi OBr and BiOIO₃ were synthesized by hydrothermal method,and a series of Bi OBr/BiOIO₃ composites were synthesized by ultrasonic impregnation method.The phase structure and chemical bond of the material were analyzed by XRD and FT-IR,and the photoluminescence spectrum confirmed that the composite phase Bi OBr/BiOIO₃ had lower photogenerated carrier recombination efficiency;Bi OBr/BiOIO₃ system had better simulated sunlight degradation of Rh B and CIP,the degradation ratio of Rh B and CIP reached 98.25%and 82.6%after photoreaction for60 min and 120 min,and 1.4-Bi OBr/BiOIO₃ still had a degradation rate of85%for Rh B after 5 repeated experiments.The above;quenching experiments prove that the main active species in this system is superoxide radical（·O₂^-）,and holes（h⁺）play an important auxiliary role,and the Bi OBr/BiOIO₃ system has good stability.（2）BiOIO₃ and Bi₂O₄ were synthesized by hydrothermal method,and a series of BiOIO₃/Bi₂O₄ composites were synthesized by ultrasonic impregnation method.Compared with the single-phase catalyst,the composite material showed stronger light-receiving ability.The PL results showed that the addition of Bi₂O₄ could efficiently limit the electron-hole recombination,and the BiOIO₃/Bi₂O₄ system had better simulated sunlight degradation of rhodamine.B and ciprofloxacin（CIP）performance after 60min and 120 min visible light irradiation.The dislodge ratio of Rh B and CIP by 0.9-BiOIO₃/Bi₂O₄ composite was 97.6%and 85.4%.After 5 cycles of experiments,the degradation rate of Rh B by the composite material was over 90%.This composite catalyst has high catalytic degradation.The performance is mainly due to its high electron-hole separation rate,high inhibition rate,and better light absorption ability.（3）First,BiOIO₃ was prepared by hydrothermal method,and then BiOIO₃/Bi₄O₅I₂ composite material was synthesized in one step by in situ growth method.The prepared materials were characterized and analyzed by a series of methods such as XRD,SEM,TEM,XPS,and BET.BiOIO₃/Bi₄O₅I₂ system has a wider optical response range and lower carrier recombination efficiency than the two single phases;photocatalytic degradation experiments show that BiOIO₃/Bi₄O₅I₂ system has better sunlight photocatalytic removal representation,after 60 min and 120 min Under visible light irradiation,the removal rate of Rh B and CIP by 0.6-BiOIO₃/Bi₄O₅I₂ can reach 97.13%and 86.1%.The preliminary judgment is that due to the successful recombination of BiOIO₃ and Bi₄O₅I₂,the energy levels of the two materials are matched,and the construction of the heterojunction improves the lifetime of the electrons.