Enhancement of Photocatalytic Activity of Bi₂O₃–BiOI Composite Nanosheets through Vacancy Engineering

Abstract

Vacancy engineering is an effective strategy to enhance solar‐driven photocatalytic performance of semiconductors. It is highly desirable to improve the photocatalytic performance of composite nanomaterials by the introduction of vacancies, but the role of vacancies and the heterostructure in the photocatalytic process is elusive to the composite nanomaterials. Herein, the introduction of I vacancies can significantly enhance the photocatalytic activity of Bi2O3–BiOI composite nanosheets in a synergistic manner. The excellent photocatalytic performance of the Bi2O3–BiOI composites is attributed to the combination of Bi2O3 and BiOI and the existence of I vacancies in Bi2O3–BiOI composites. Specifically, density functional theory calculation shows that the existence of I vacancies would create a new electric states vacancy band below the conduction band of BiOI and thus can reduce the bandgap of BiOI nanosheets. This greatly facilitates the scavenging of the photogenerated electron on the surface of BiOI by Bi2O3, therefore, enhancing the overall photocatalytic activity of the composites. The enhanced photocatalytic efficiency is demonstrated by the degradation of tetracycline (TC), which reaches 96% after 180 min and by the high total organic carbon (TOC) removal (89% after 10 h visible light irradiation). This study provides a novel approach for the design of high‐performance composite catalysts.

Achieving Superior Electrocatalytic Performance by Surface Copper Vacancy Defects during Electrochemical Etching Process

“…[23] Positron annihilation spectroscopy (PAS) was performed in this study to further investigate the type and concentration of vacancy defects in the catalyst surface. [37,38] The PAS shows that both the PtCu and V Cu -PtCu catalysts are similar in term of the shape of the spectra (Figure 3 e). As seen from the lifetime parameters, both the PtCu and V Cu -PtCu catalysts exhibit two lifetimes (Table S1).…”

Harmonizing the Electronic Structures on BiOI with Active Oxygen Vacancies toward Facet‐Dependent Antibacterial Photodynamic Therapy

“…[18] Moreover, the obvious peak at 531.5 eV verifies the presence of oxygen vacancies in two BOI samples. [19] In addition, The VB maximum of BI-001 and BI-110 are 1.71 and 1.44 eV, respectively (Figure 2a).…”

Bi2WO6–BiOCl heterostructure with enhanced photocatalytic activity for efficient degradation of oxytetracycline

“…Two-dimensional (2D) lamellar structures are promising photocatalysts owing to their high emission quantum yields, large charge carrier mobility, and short bulk diffusion length 5 . Bismuth oxychloride (BiOCl), with a special layer structure consisting of [Bi 2 O 2 ] 2+ layers sandwiched between two slabs of halogen ions, has shown favorable photocatalytic performance and stability 6 .…”