Efficient Advanced Oxidation Process (AOP) for Photocatalytic Contaminant Degradation Using Exfoliated Metal-Free Graphitic Carbon Nitride and Visible Light-Emitting Diodes

Catalysts

AdeemGhaffar Rana¹  Mirjana Minceva¹  Minoo Tasbihi²  Michael Schwarze² 

[1] Biothermodynamics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Maximus-von-Imhof-Forum 2, 85354 Freising, Germany;Department of Chemistry, Technische Universität Berlin, Str. des 17. Juni 124, 10623 Berlin, Germany;

关键词: g-C₃N₄;    photocatalysis;    LEDs;    wastewater treatment;    phenol;   

DOI  :  10.3390/catal11060662

来源: DOAJ

【 摘 要 】

The photocatalytic performance of metal-free graphitic carbon nitride (g-C₃N₄) was examined using visible light-emitting diodes (LEDs). A comparative and parametric study was conducted using the photocatalytic degradation of phenol as a model reaction. The g-C₃N₄ photocatalyst was synthesized from melamine using thermal condensation, followed by a thermal exfoliation that increases the catalyst surface area from 11 to 170 m²/g. Different characterization techniques, namely X-ray powder diffraction, X-ray photoelectron spectroscopy, nitrogen adsorption using the Brunauer–Emmett–Teller method, ultraviolet-visible (UV–vis) spectroscopy, transmission electron microscopy, photoluminescence spectroscopy (PL), and zeta potential analysis, were used to characterize the photocatalyst. A comparison of the photodegradation experiments conducted with a full-spectrum xenon lamp and a custom-made single-wavelength LED immersion lamp showed that the photocatalyst performance was better with the LED immersion lamp. Furthermore, a comparison of the performance of exfoliated and bulk g-C₃N₄ revealed that exfoliated g-C₃N₄ completely degraded the pollutant in 90 min, whereas only 25% was degraded with bulk g-C₃N₄ in 180 min because the exfoliated g-C₃N₄ enhances the availability of active sites, which promotes the degradation of phenol. Experiments conducted at different pH have shown that acidic pH favors the degradation process. The exfoliated g-C₃N₄ has shown high photocatalytic performance in the photodegradation of other phenolic compounds, such as catechol, m-cresol, and xylenol, as well.

【 授权许可】

Unknown