CQDs/biochar from reed straw modified Z-scheme MgIn2S4/BiOCl with enhanced visible-light photocatalytic performance for carbamazepine degradation in water. (January 2022)

• Record Type: Journal Article
• Authors: Qi, Kemin; Song, Mengxi; Xie, Xiaoyun; Wen, Yuan; Wang, Zirun; Wei, Bin; Wang, Zhaowei
• Is Part Of: Chemosphere. Volume 287:Part 2(2022)
• Publication Date: 2022-01
• Subjects: MgIn2S4/BiOCl -- Carbamazepine -- Photocatalyst -- Green carbon quantum dots -- Biochar; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.132192
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The application of environmental-friendly and sustainable green materials in constructing photocatalysts to degrade pharmaceuticals and personal care products (PPCPs) attracts more attention. Herein, biochar (BC) or biomass carbon quantum dots (CQDs) were used to modify MgIn2 S4 /BiOCl (MB) heterojunction photocatalyst with Z-scheme structure, and improved the photocatalytic degradation performance for carbamazepine (CBZ) in the aqueous solution. Both BC and CQDs could form electron transfer interface with MB heterojunction, resulting in the photodegradation rate of MgIn2 S4 /BiOCl/CQDs (MBC, 96.43%) and MgIn2 S4 /BiOCl/BC (MBB, 88.09%) to CBZ within 120 min visible-light irradiation, which were significantly higher than that of MB (65.84%). Moreover, photoelectrochemical and photoluminescence tests verified that CQDs could act as a bridge for storing and transferring electrons in the entire Z-scheme system. Thence, compared with MBB, MBC could produce more OH and O2 − under the visible light, which was indicated by the results of radical quenching experiments and electron paramagnetic resonance. Interestingly, under the natural sunlight, the photocatalytic performance of MBC to CBZ was even better than under laboratory conditions. In addition, the TOC removal efficiencies of MBB and MBC could reach 85.09% and 93.79% respectively, and ECOSAR program was utilized to further evaluate the eco-toxicity of CBZ and the intermediates towards fish, daphnid, and green algae, indicating that the photocatalytic process involving MBB and MBC showed outstanding toxicity reduction performance. Finally, compared with other composites, MBB and MBC showed higher photocatalytic performance and lower energy consumption, which would provide a green strategy for biochar materials in the photocatalytic treatment of PPCPs in water. Graphical abstract: Image 1 Highlights: Biochar (BC) and biomass carbon quantum dots (CQDs) were prepared from reed straw. MBB and MBC showed perfect ability of carbamazepine degradation and mineralization. Under LED irradiation, MBC could produce more reactive oxygen species than MBB. Carbamazepine photodegradation in two systems was a toxicity-reduction process. MBB and MBC had low electrical energy per order in degradation of carbamazepine.