Flexible carbon-fiber/g-C3N4 nanosheet array as recyclable photocatalysts and photoelectrocatalysts

Sci Rep. 2025 Jul 1;15(1):21090. doi: 10.1038/s41598-025-04701-1.

Abstract

In the field of photocatalytic degradation, the separation and recycle technology of powdery g-C3N4 after usage has not been mature so far as well as the secondary pollution problems for large-scale industrial applications. In this thesis, through depositing g-C3N4 nanosheets onto the surface of flexible carbon fiber textiles using chemical vapor deposition (CVD) method, separable and recyclable carbon-fiber/g-C3N4 nanosheet array was fabricated by method. The photocatalytic, electrocatalytic, and photoelectrocatalytic performance of carbon-fiber/g-C3N4 nanosheet array are studied. The results of in-situ XPS spectra confirm that the photoexcited electrons migrate from g-C3N4 nanosheets to carbon fibers in the carbon-fiber/g-C3N4 nanosheet array under light illumination, which enhances the separation of photo-generated electrons and holes. The applied potential further accelerates the migration of photogenerated electrons towards the cathode, thereby fostering a synergistic interplay between electrochemical and photophysical processes. Upon completion of a 240-minute photoelectrocatalytic treatment, the degradation efficiency of 2,4-dinitrophenol attains a remarkable 99.5% level. The assembly strategy developed herein significantly reduce the separable and recyclable cost of powdery photocatalysts and offer valuables references for industrial application of photocatalysis and photoelectrocatalysis. Our method may provide a general methodology in the design of separable and recyclable photocatalysts with broad applications in environment-related fields.

Keywords: Flexible carbon-fiber; Photocatalyst; Photoelectrocatalyst; g-C3N4 nanosheet.