Annealing construction of in situ heterojunction for photocatalytic degradation of bisphenol A

Abstract

Here, we report the synthesis of bismuth oxyiodide (BiOI) photocatalysts with oxygen vacancy defects by a one-pot solvothermal method followed by annealing in a nitrogen atmosphere. This method allows the oxygen vacancy concentration to be tuned and provides new insights into defect engineering of photocatalytic materials. We found that the Bi2O3/BiOI heterojunction formed after annealing at 400°C significantly improves the photocatalytic performance, which provides a new strategy for the optimal design of structures for efficient photocatalysts. Using a combination of characterization techniques such as X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), as well as density-functional theory (DFT) calculations, we have elucidated the photocatalytic mechanism of the Bi2O3/BiOI heterojunctions, highlighting their role in facilitating the photogenerated charge-carrier separation and transfer. The optimized A-B40 samples exhibited photocatalytic degradation efficiencies of up to 99.7% for bisphenol A (BPA), highlighting their potential for remediation of environmental pollutants. This study presents a method for the preparation of high-performance BiOI-based photocatalysts, which offers valuable theoretical and experimental prospects for the development of eco-friendly photocatalytic materials.