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Facile Synthesis of Sillén-Aurivillius Layered Oxide Bi7Fe2Ti2O17Cl with Efficient Photocatalytic Performance for Degradation of Tetracycline. Catalysts 2022. [DOI: 10.3390/catal12020221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The development of an efficient and environment-friendly photocatalyst for antibiotics degradation is of great significance and still remains a major challenge. Herein, a novel Sillén-Aurivillius layered oxide Bi7Fe2Ti2O17Cl is successfully synthesized via a one-step flux route (noted as F-BFTOC) and solid-state reaction (noted as S-BFTOC). The as-prepared F-BFTOC manifests the enhanced visible-light photocatalytic performance towards tetracycline (TC) degradation compared with Bi4NbO8Cl and its degradation efficiency reaches 90% within 90 min. Additionally, the proposed degradation pathway and photocatalytic mechanism are systematically investigated by liquid chromatography tandem-mass spectrometry (HPLC-MS), active species trapping test, electron spin resonance (ESR) and first-principles calculations. The superior degradation of antibiotics is primarily derived from the photo-generated h+, and radical ·O2− as the dominant active species. More importantly, the F-BFTOC exhibits excellent cycle stability and TC is ultimately transformed into non-toxic open-loop products. Simultaneously, Rhodamine B (RhB) as a typical organic pollutant is further employed to evaluate the photocatalytic activity of F-BFTOC, and 98% of the degradation efficiency is achieved. BFTOC as a multifunctional photocatalyst for pollutant degradation offers a new insight for Sillén-Aurivillius photocatalytic in the field of water purification.
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Abstract
An increase of carrier concentration is one of the most important routes for enhancing the catalytic performance of semiconductor photocatalysts. In this study, the Sillén–Aurivillius oxychloride Bi4NbO8Cl with hole doping was successfully prepared by a solid-state reaction method. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible diffuse reflectance spectra (UV–vis DRS), X-ray photoelectron spectrometry (XPS) and photoluminescence spectra (PL) were used to characterize and analyze the prepared samples. The experimental results and density functional theory calculations demonstrate that hole doping can be formed in Bi4NbO8Cl by inserting zinc into the niobium site, and the photocatalytic activity can be improved by introducing additional holes into Bi4NbO8Cl. The photogenerated hole (h+) is considered to be the main active species to degrade trypan blue (TB) through trapping experiments. The optimal photocatalyst of Bi4Nb0.8Zn0.2O8Cl exhibits excellent photocatalytic activity in degradation of trypan blue under visible light irritation. Moreover, a possible photocatalytic degradation mechanism is discussed according the experimental and analytical results.
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