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

Abstract

In the field of photocatalytic degradation, the separation and recycle technology of powdery g-C3N4 after usage has not been mature, which causes secondary pollution problems for large-scale industrial applications. In this paper, carbon-fiber/g-C3N4 nanosheet arrays were fabricated by chemical vapor deposition(CVD) under argon protection, and the optical, electrochemical and photocatalytic performance of carbon-fiber/g-C3N4 nanosheet arrays were studied. The results indicated that carbon-fiber/g-C3N4 nanosheet arrays generated photon-excited electrons and holes under visible light irradiation during photocatalytic process. The excellent electrical conductivity of carbon fiber could trap photon-excited electrons in conduction band of g-C3N4 nanosheet and creat holes in valence band of g-C3N4 nanosheet. 20.7%, 33.5% and 99.5% of 2, 4-dinitrophenol were degraded by photocatalysis, electrocatalysis and photoelectrocatalysis of carbon-fiber/g-C3N4 nanosheet arrays within 240 min. The external voltage further enhanced the separation of photo-generated electrons and holes, which made the photoelectrocatalysis of carbon-fiber/g-C3N4 nanosheet arrays exerted unexpected performance through synergistic interactions of photocatalysis and electrocatalysis. The assembly of powdery photocatalysts and carbon fibers textile might provide a general methodology in the design of separable and recyclable photocatalysts with broad applications in environment-related fields. The assembly strategy developed herein significantly reduced the separable and recyclable cost of powdery photocatalysts and offered valuables references for industrial application of photocatalysis and photoelectrocatalysis.

Keywords

• flexible carbon-fiber
• g-c3n4 nanosheet
• photocatalyst
• photoelectrocatalyst