Simultaneous photocatalytic tetracycline oxidation and chromate reduction a jointed synchronous pathway upon Z-scheme BiOCl/AgBr: insight into intermediates and mechanism

• Published in: Environmental science. Nano 2022-05, Vol.9 (5), p.178-1793
• Main Authors: Zhai, Zicheng, Ren, Kaixu, Zheng, Xiangyang, Chen, Yigang, Dong, Yuming, Shi, Haifeng
• Format: Article
• ISSN: 2051-8153; 2051-8161
• DOI: 10.1039/d2en00028h

The coexistence of heavy metals and antibiotics is not only unprecedently detrimental to modern wastewater but also poses unprecedented challenges to pollution elimination, arousing urgent demand for highly efficient photocatalysts as a solution. Herein, AgBr (AB) nanoparticles were chosen to load onto Bi 12 O 17 Cl 2 (B 12 ) nanosheets for their morphology and intrinsic redox potentials. The resultant 2D/0D Bi 12 O 17 Cl 2 /AgBr (B 12 /AB) composites were exposed to hexavalent chromium (Cr( vi )) and tetracycline (TC) both individually and simultaneously to examine their removal capacity. Notably, the B 12 /AB 1 : 1 sample exhibited meritorious photocatalytic activity when exposed to the mixture solution of Cr( vi ) and TC, with a boost in Cr( vi ) reduction efficiency by 9.2-folds, while the TC degradation was also improved by 9%. The enhancement could be attributed to the 2D/0D morphology observed in TEM images, which provides abundant reaction sites, and the Z-scheme charge transfer pathway that inhibits the recombination of photogenerated charge carriers, while retaining the high redox potentials. Furthermore, the pathway of TC degradation in complex pollutant solutions was investigated with a liquid chromatography (LC) coupled with mass spectrometer (MS). The B 12 /AB Z-scheme system offers complimentary coordination that creates a jointed synchronous pathway for removing Cr( vi ) and TC simultaneously. Therefore, this work could shed more light on the simultaneous photocatalytic removal of heavy metals and organic pollutants in wastewater. A 2D/0D Bi 12 O 17 Cl 2 /AgBr Z-scheme photocatalyst provides a jointed synchronous pathway for simultaneous Cr( vi ) and TC removal.