부산대학교 도서관

Utilizing the cost-effective natural clay and surface heterojunction engineering to synergistically constructan efficient heterojunction system and promote the separation of photogenerated charges is anappealing strategy for achieving superior photocatalytic activity. In this study, BiOBr/BiOI step-scheme(S-scheme) heterojunction in-suit grown on magnetized bentonite (MBT) was first engineered via facileand mild coprecipitation coupling microwave solvothermal process. The optimized magnetic bentonite/BiOBr/BiOI (MBT25/BiOBr/BiOI, the mass ratio of MBT to BiOBr/BiOI was 25%) attained the largest reactionrate constant (k = 0.021 min1) in tetracycline (TC) photocatalytic degradation within 80 min visible-lightirradiation. In addition, the reaction rate constant k of MBT25/BiOBr/BiOI for TC degradation was 10.51folds higher than that of pristine BiOI. Significantly, the characterization results demonstrated thatMBT effectively assisted the pinecone-like morphology formation of BiOBr/BiOI and endowed the wonderfulmagnetic-separation ability for MBT25/BiOBr/BiOI. Additionally, MBT ingeniously introduced atthe interface could couple with S-scheme heterojunction between BiOBr and BiOI to synergistically boostthe separation and transfer of photogenerated charges. As expected, superior photochemical propertiesand efficient production of active species over MBT25/BiOBr/BiOI were confirmed. Notably, recyclingexperiments verified the wonderful photocatalytic stability and high recovery efficiency of MBT25/BiOBr/BiOI. Furthermore, the abundant O2and OH active species led to hydroxylation, dealkylation,deamidation and ring opening of TC molecules. A synergistically enhanced mechanism over S-schemeMBT25/BiOBr/BiOI was clarified based on band structure calculations. This study offers an innovative perspectiveto design multifunctional photocatalysts with superior activity by integrating properties of magnetizedclay and S-scheme heterojunction.