New insights of metal free 2D graphitic carbon nitride for photocatalytic degradation of bisphenol A

Rama Shanker Sahu; Yang-Hsin Shih; Wen-Ling Chen

doi:10.1016/j.jhazmat.2020.123509

New insights of metal free 2D graphitic carbon nitride for photocatalytic degradation of bisphenol A

J Hazard Mater. 2021 Jan 15:402:123509. doi: 10.1016/j.jhazmat.2020.123509. Epub 2020 Jul 17.

Authors

Rama Shanker Sahu¹, Yang-Hsin Shih², Wen-Ling Chen³

Affiliations

¹ Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 106, Taiwan, ROC. Electronic address: ramashanker.sahu@gmail.com.
² Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 106, Taiwan, ROC. Electronic address: yhs@ntu.edu.tw.
³ Institute of Food Safety and Health, College of Public Health, National Taiwan University, 17 Xuzhou Rd., Taipei, 100, Taiwan, ROC; Department of Public Health, College of Public Health, National Taiwan University, 17 Xuzhou Rd., Taipei, 100, Taiwan, ROC.

PMID: 32717544
DOI: 10.1016/j.jhazmat.2020.123509

Abstract

Polymeric oxygen rich exfoliated graphitic carbon nitride (exfoliated GCN, EGCN) was synthesized by the acid treatment of bulk GCN. The photocatalyst was characterized using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and point of zero charge. EGCN shows high valance band hole transfer under short-time visible light (λ > 420 nm) exposure for photocatalytic mineralization of bisphenol A (BPA). Enhanced BPA removal was achieved by EGCN (99 %) due to formation of OH^● radicals (H₂O/h_VB⁺ →OH^●/H⁺). Major factors affecting BPA degradation including catalyst dose, wide pH range, and pollutant concentration were optimized. Repeated cycles of BPA degradation were performed with negligible rate decreased from 0.045 to 0.029 min^-1. The degradation profile and plausible reaction mechanism of BPA was established and well justified by the byproducts identified by mass analysis HR-ESI-MS. Therefore, the as-synthesized metal free EGCN, active under visible light, offers a new platform for complete mineralization of byproducts of halogenated organic contaminants.

Keywords: Degradation mechanism; Exfoliated graphitic carbon nitride; Metal free catalyst; Photocatalysis; Visible light.

Publication types

Research Support, Non-U.S. Gov't