Oxygen vacancy rich Bi2O4-Bi4O7-BiO2-x composites for UV–vis-NIR activated high efficient photocatalytic degradation of bisphenol A

• Published in: Journal of hazardous materials 2020-01, Vol.382, p.121121-121121, Article 121121
• Main Authors: Jia, Yuefa, Li, Shiping, Ma, Haoxuan, Gao, Jianzhi, Zhu, Gangqiang, Zhang, Fuchun, Park, Jun Young, Cha, Sangwon, Bae, Jong-Seong, Liu, Chunli
• Format: Article
• Language: English
• Subjects: Bi2O4-Bi4O7-BiO2-x; DFT calculations; Near-infrared light; Oxygen vacancy; Photocatalytic
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2019.121121

Ternary mixed valent bismuth oxides (Bi2O4-Bi4O7-BiO2-x) with rich oxygen vacancy acting as electron mediator have been successfully prepared through one-pot hydrothermal strategy, which demonstrates greatly improved UV, visible, and near-infrared (NIR) light-driven photocatalytic performance for photodegradation of bisphenol A (BPA). [Display omitted] •Bi2O4-Bi4O7-BiO2-x with rich oxygen vacancy photocatalyst was fabricated.•Bi2O4-Bi4O7-BiO2-x revealed enhanced full spectrum driven photocatalytic activity.•A full spectrum photocatalytic mechanism was proposed by experiments and DFT study. To fully utilize the solar light, photocatalyst with broad spectrum response from UV to near-infrared (NIR) is desirable. In this work, ternary mixed valent Bi2O4-Bi4O7-BiO2-x with rich oxygen vacancy has been synthesized through one-pot hydrothermal treatment of NaBiO3. The results showed that through adjusting the hydrothermal conditions, oxygen vacancy-rich Bi2O4-Bi4O7-BiO2-x nanocomposites with much higher efficiency than single or mixed bismuth oxides (Bi2O4, Bi4O7, BiO2-x and Bi4O7-BiO2-x,) can be synthesized for photocatalytic degradation of bisphenol A (BPA) under UV, visible, and NIR light irradiation. In addition, the liquid chromatography-mass spectrometer (LC–MS) characterization demonstrated that BPA was oxidized to 4-isopropenyphenol first and the rings were opened sequentially under NIR light irradiation. Further detection of reactive species indicated that holes, O2−, and OH were the main oxidizing species in the degradation system. The experimental observations and density functional theory (DFT) calculations suggested that both type-II and the Z-scheme charge transfer with oxygen vacancies as electrons and holes mediators were formed at the interfaces of Bi2O4, Bi4O7, and BiO2-x, resulting in a very efficient separation of photogenerated charge carriers in the composite. This work adds to the growing potential of mixed valent bismuth oxides based photocatalysts and is expected to accelerate the pace of the development of new-generation photocatalysts with high efficiency utilizing full-spectrum solar light.