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

Yan Gu,Qinfang Zhang,Jikun Chen,Fang Yu

doi:10.3390/catal12020221

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.

Highlights

A variety of contaminations out of water lead to the accumulation of toxic pollutants in environment, which seriously affects waterbody biodiversity and even the health of humans [1,2]
S-BFTOC powders were prepared using the conventional solid-state reaction and calcined at 750 ◦ C for 12 h, and F-BFTOC powders were synthesized through liquid-state flux method
The Bi-based Sillén-Aurivillius Bi7 Fe2 Ti2 O17 Cl was successfully fabricated by means of a one-step flux method

Summary

Introduction

A variety of contaminations out of water lead to the accumulation of toxic pollutants in environment, which seriously affects waterbody biodiversity and even the health of humans [1,2]. Water pollutants are attributable to immoderate antibiotics, which have attracted significant attention in recent decades. Very limited amounts of antibiotics are able to be eliminated by conventional biological and chemical technologies [3,4,5]. Tetracycline (TC) as a class of representative antibiotic is impossible to be completely metabolized by natural degradation and biodegradability. A portion of the high toxicity of the intermediate products of TC is excreted, which poses a huge threat to the aquatic ecosystem [6]. The development of a simple and effective strategy to degrade subaqueous TC is of considerable importance

Methods

Results

Conclusion