Highly reusable Bi2O3/electron-Cu-shuttle in-situ immobilized polyacrylonitrile fibrous mat for efficient photocatalytic degradation of methylene blue and rhodamine B dyes

Abstract

Organic semiconductor-based photocatalysts have been alluring due to their edge over inorganic photocatalysts. In this study, a reusable copper-bismuth oxide/polyacrylonitrile (Cu-Bi₂O₃/PAN) fibrous mat was prepared by fast-process flame spray pyrolysis and electrospinning for photocatalytic degradation of methylene blue (MB) and rhodamine B (RhB) dyes. The results confirmed a well-defined morphology of Cu-Bi₂O₃/PAN fibers and good coordination of flame-made Cu-Bi₂O₃ particles with the functional groups of PAN. The Cu-Bi₂O₃/PAN fibrous mat exhibits remarkable photocatalytic performance of 96.2% MB and 98.6% RhB degradation, with a reaction rate as high as about 4.5- and 10.2-times than that of flame-made Cu-Bi₂O₃ particles and PAN under neutral condition, even after 10 cycles. The Cu-Bi₂O₃/PAN exhibits complete degradation of MB and RhB in 90 and 150 min under alkaline and slightly acidic conditions, respectively. The synergistic effect of Cu-Bi₂O₃ and coordination bond between particles and functional groups of PAN promoted carrier migration, suppressed recombination of carriers and provided abundant radicals on the surface of the mat. Superoxide and hydroxyl radicals were the major active species involved in the degradation of RhB and MB, respectively. This work provides an insight into designing the Cu-metal-shuttle based photocatalysts to optimize fibrous mat application in water remediation.

Keywords: Dye degradation; Electrospinning; Flame spray pyrolysis; Nanoparticles; Photocatalysis; Polyacrylonitrile.