Zejian Dong,Na Zhang,Shuangbao Wang,Yuying Liu,Lifeng Zhang,Xing Chen,Langli Luo
Atomic defects are critical to tuning the physical and chemical properties of functional materials such as catalysts, semiconductors, and 2D materials. However, direct structural characterization of atomic defects, especially their formation and annihilation under practical conditions, is challenging yet crucial to understanding the underlying mechanisms driving defect dynamics, which remain mostly elusive. Here, through in situ atomic imaging by an aberration-corrected environmental transmission electron microscope (AC-ETEM), we directly visualize the formation and annihilation mechanism of planar defects in monoclinic WO3 on the atomic scale in real time. We captured the atomistic process of the nucleation dynamics of the dislocation core in the [010] direction, followed by its propagation to form a planar defect. Corroborated by density functional theory-based calculations, we rationalize the formation of dislocation through O extraction from bridge sites followed by an atomic channeling process. These in situ observations shed light on the defect dynamics in oxides and provide atomic insights into forming and manipulating defects in functional materials.
Tetrabromobisphenol A (TBBPA), a prevalent brominated flame retardant, poses significant environmental and health risks, necessitating its removal. In this study, WO3 with different structures was synthesized for TBBPA photodegradation under visible light using H2O2 and O2 as oxidants. The catalyst exhibited robust stability and reusability, rendering it suitable for practical applications. The crystalline structure and surface structure of WO3 controlled its catalytic activity towards TBBPA photodegradation. Monoclinic WO3 with the (022) plane was found to be the most active for ˙O2− active species generation from H2O2 and thus active for TBBPA degradation. Degradation product analysis showed that the catalyst was active not only for the removal of TBBPA, but also for the debromination of TBBPA. Nearly 100% debromination was achieved.
危险品化学品经营许可证（带存储）