Anchoring bismuth oxybromo-iodide solid solutions on flexible electrospun polyacrylonitrile nanofiber mats for floating photocatalysis

Shuai Liu; Pingping Liang; Jie Liu; Jiayu Xin; Xinghua Li; Changlu Shao; Xiaowei Li; Yichun Liu

doi:10.1016/j.jcis.2021.11.046

Anchoring bismuth oxybromo-iodide solid solutions on flexible electrospun polyacrylonitrile nanofiber mats for floating photocatalysis

J Colloid Interface Sci. 2022 Feb 15;608(Pt 3):3178-3191. doi: 10.1016/j.jcis.2021.11.046. Epub 2021 Nov 13.

Authors

Shuai Liu¹, Pingping Liang², Jie Liu², Jiayu Xin², Xinghua Li³, Changlu Shao⁴, Xiaowei Li², Yichun Liu²

Affiliations

¹ Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory of UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, People's Republic of China; College of Science, Northeast Electric Power University, 169 Changchun Street, Jilin 132012, People's Republic of China.
² Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory of UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, People's Republic of China.
³ Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory of UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, People's Republic of China. Electronic address: lixh781@nenu.edu.cn.
⁴ Center for Advanced Optoelectronic Functional Materials Research, and Key Laboratory of UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, 5268 Renmin Street, Changchun 130024, People's Republic of China. Electronic address: clshao@nenu.edu.cn.

PMID: 34802760
DOI: 10.1016/j.jcis.2021.11.046

Abstract

Constructing floating photocatalysts with highly efficient visible-light utilization is a promising approach for practical photocatalytic wastewater treatment. In this study, we anchored bismuth oxybromo-iodide (BiOBr_xI_1-x (0 ≤ x ≤ 1)) on flexible electrospun polyacrylonitrile (PAN) nanofiber mats to create BiOBr_xI_1-x@PAN nanofibers with tunable light absorption properties as floating photocatalysts at room temperature. As x increased, the photocatalytic activity of the BiOBr_xI_1-x@PAN nanofibers with similar loading content initially increased, and then decreased, for the degradation of bisphenol A (BPA) and methyl orange (MO) under visible-light irradiation (λ > 420 nm) conditions. The BiOBr_xI_1-x@PAN (0 < x < 1) nanofibers exhibited better photocatalytic performance compared to the BiOBr@PAN and BiOI@PAN nanofibers. Under visible-light irradiation, the BPA degradation rate of the BiOBr_0.5I_0.5@PAN nanofibers was 1.9 times higher than that of the BiOI@PAN nanofibers, while the BiOBr@PAN nanofibers had no noticeable degradation performance. The MO degradation rate of the BiOBr_0.5I_0.5@PAN nanofibers was 2.5 and 3.2 times higher than that of the BiOBr@PAN and BiOI@PAN nanofibers, respectively. The enhanced performance possibly originated from a balance between the light absorption and redox capabilities, along with efficient separation of electron-hole pairs in the BiOBr_0.5I_0.5@PAN nanofibers, as determined by ultraviolet-visible diffuse reflectance spectroscopy, X-ray photoelectron spectra analysis of the valence bands, and photocurrent response characterization. Compared to the powder structures, the BiOBr_xI_1-x@PAN nanofibers showed enhanced performance due to the excellent dispersion and immobilization of the BiOBr_xI_1-x solid solution, which provided more active sites during photocatalytic degradation. In addition, their flexible self-supporting structures allowed for floating photocatalysis near the water surface. They could be reused directly without separation and maximized the absorption of visible light during the photocatalytic reaction. Therefore, these solid-solution-based floatable nanofiber photocatalysts are good potential candidates for wastewater treatment applications.

Keywords: BiOBr(x)I(1-x); Electrospinning; Floating photocatalysis; Photocatalyst; Solid solution.