Visible-light responsive electrospun nanofibers based on polyacrylonitrile-dispersed graphitic carbon nitride

Abstract

A visible-light responsive photocatalyst, polyacrylonitrile-dispersed graphitic carbon nitride nanofibers (g-C₃N₄/PAN nanofibers), was synthesized by electrospinning. The g-C₃N₄ is dispersed uniformly in the nanofibers, which helps it overcome the defects of easy aggregation and difficult recycling of powder catalysts. The model substrate, rhodamine B (RhB), could be adsorbed rapidly into the PAN nanofibers and decomposed efficiently in situ simultaneously in the presence of the g-C₃N₄ over a wide pH range under visible light irradiation. As a fibrous catalyst, the g-C₃N₄/PAN nanofibers were quite simple to recycle, and the catalytic activity maintained a high level without obvious decline after being reused several times. In addition, based on the intermediates detected by ultra performance liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry, N-de-ethylation chromophore cleavage and ring-opening mineralization are the main processes in RhB degradation. Finally, a possible mechanism was proposed, in which the hole along with the superoxide radical mainly contribute to the oxidative degradation of RhB.