Electron transfer channel in BiOBr/Bi2O3 heterojunction enhanced photocatalytic removal for fluoroquinolone antibiotics

In-situ assembling novel N-Ti3C2/BiOClxBr1-x composites with enhanced photocatalytic degradation and nitrogen reduction activity

Herein, a collection of novel N-Ti3C2/BiOClxBr1-x composites are fabricated via a simple in-situ sonochemical process. Not only the preparation method for N-Ti3C2 but also the photocatalytic system of N-Ti3C2/BiOClxBr1-x are firstly developed. Multiple characterizations jointly demonstrate the successful fabrication of the composites. Compared to that of BiOClxBr1-x, the maximum improvements of 1.16, 1.25 and 1.26 folds are severally confirmed for the photocatalytic degradation of levofloxacin, Rhodamine B, and methylene blue over N-Ti3C2/BiOClxBr1-x composites. In addition, through radicals trapping tests, the primary active species in photocatalytic degradation process are verified to be O2-. Moreover, N-Ti3C2/BiOClxBr1-x composites also exhibit 1.18 and 1.14 times enhancements for NH3 production compared with that of BiOClxBr1-x with or without the presence of methanol, respectively. In addition, the maximum improvements of photo-current and photo-potential for BiOClxBr1-x are 1.29 and 1.86 folds with the introduction of N-Ti3C2, respectively. The enhanced photocatalytic activity of N-Ti3C2/BiOClxBr1-x composites is owing to the heightened light absorption, increased specific surface area, and accelerated separation of photoinduced carriers. Additionally, the stable photocatalytic properties of N-Ti3C2/BiOClxBr1-x are confirmed by three photocatalytic recycle tests on pollutant degradation and nitrogen reduction combined with X-ray diffraction patterns before and after three recycles. This study suggests that N-Ti3C2 is an efficient ornamentation for boosting photocatalytic activity ofBiOClxBr1-x, which can also be expanded as a promising modifier for other semiconductors.

Self-Assembly of Bi2Sn2O7/β-Bi2O3 S-Scheme Heterostructures for Efficient Visible-Light-Driven Photocatalytic Degradation of Tetracycline

Fabrication of S-scheme heterojunctions with enhanced redox capability offers an effective approach to address environmental remediation. In this study, high-performance Bi₂Sn₂O₇/β-Bi₂O₃ S-scheme heterojunction photocatalysts were fabricated via the in situ growth of Bi₂Sn₂O₇ on β-Bi₂O₃ microspheres. The optimized Bi₂Sn₂O₇/β-Bi₂O₃ (BSO/BO-0.4) degradation efficiency for tetracycline hydrochloride was 95.5%, which was 2.68-fold higher than that of β-Bi₂O₃. This improvement originated from higher photoelectron-hole pair separation efficiency, more exposed active sites, excellent redox capacity, and efficient generation of ^·O₂ ^- and ^·OH. Additionally, Bi₂Sn₂O₇/β-Bi₂O₃ exhibited good stability against photocatalytic degradation, and the degradation efficiency remained >89.7% after five cycles. The photocatalytic mechanism of Bi₂Sn₂O₇/β-Bi₂O₃ S-scheme heterojunctions was elucidated. In this study, we design and fabricate high-performance heterojunction photocatalysts for environmental remediation using S-scheme photocatalysts.

Synthesis of a ternary Bi2O3/CQDs/rGO photocatalyst to active peroxymonosulfate for the removal of tetracycline hydrochloride

In this paper, the ternary Bi₂O₃/CQDs/rGO photocatalyst was synthesized by a solvothermal method. The as-fabricated Bi₂O₃/CQDs/rGO composites showed stronger visible-light response and higher photocatalytic activity. In order to further enhance the degradation efficiency of tetracycline hydrochloride, Bi₂O₃/CQDs/rGO was used to activate peroxymonosulfate under visible-light irradiation. The degradation efficiency increased sevenfold, indicating that the synergistic effect of photocatalysis and peroxymonosulfate activated by photogenerated electrons could clearly increase the degradation efficiency of tetracycline hydrochloride. In addition, the photocatalytic mechanism was further proposed and verified by radical quenching experiments and electron paramagnetic resonance analysis. Thus, this study provides a new idea for the photocatalytic application of Bi₂O₃/CQDs/rGO and a contribution to the degradation of antibiotics to avoid polluting the water environment.