Facile Synthesis of Sillén-Aurivillius Layered Oxide Bi7Fe2Ti2O17Cl with Efficient Photocatalytic Performance for Degradation of Tetracycline

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.

New insights into the synthesis of Sillén–Aurivillius oxyhalides: molten salts induce interlayer halogen competing reaction

“…In this experiment, BiOX (X = Cl, Br) precursors were prepared via a chemical deposition process at room temperature with the precursor materials of KX (X = Cl, Br) and Bi(NO 3 )$5H 2 O, and more details about this process can be found in our previous works. 9,23,30 Then, BiOX (X = Cl, Br) and BaCO 3 were mixed in the stoichiometric ratio of 1 : 1 to prepare the BaBiO 2 X precursor at 700 °C for 10 h by the traditional SSR method.…”

“…However, high temperature also induces the loss of halogen [X] elements, creating deep-level defects, which serve as recombination centers, hindering the transport of photogenerated charge carriers and reducing the photocatalytic performance. 23,24 Based on this, the molten-salt synthesis (MSS) method has been widely used for the fabrication of Sillén–Aurivillius oxyhalides given that it can offer a special liquid reaction environment that expedites the diffusion rate of reactive elements and motivates the formation of high-purity and uniform reaction products. 25,26 Because Sillén–Aurivillius oxyhalides contain halogen elements (F, Cl, Br, and I), most Bi-based materials are grown with the same molten salt as halogen.…”

In situ self-assembly fabrication of ultrathin sheet-like CuS modified g–C3N4 heterojunction and its enhanced visible-light photocatalytic performance

“…To further clarify the photocatalytic mechanism of degrading MB by CuS/g-C 3 N 4 -60%, active species produced during the photocatalytic process were investigated by capturing experiments. Scavengers for trapping active species, disodium ethylenediaminetetraacetic acid (EDTA), benzoquinone (BQ) and tert-butanol (t-BuOH), are used for capturing holes (h + ), superoxide radicals (•O 2 − ) and hydroxyl radicals (•OH), respectively [37][38][39]. As shown in figure 10, comparing with the MB degradation efficiency of using CuS/g-C 3 N 4 -60% without adding any scavenger, it decreased so slightly that it can be neglected when t-BuOH was added.…”

Eco-friendly Synthesis of SrBi4Ti3,95Fe0,05O15 via Molten Salt Method

“…The plate-like (sheet) particle of Aurivillius structure was reported to have good activity photocatalytic [6]. It indicates that if we can synthesized Aurivillius compound with plate-like/sheet morphology so that will give advantage in photocatalyst applied.…”