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• A novel 2D/3D Bi 5 O 7 Br/BiOBr was prepared via one-step hydrolysis method. • The Bi 5 O 7 Br/BiOBr exhibited better visible light degrade pharmaceutical activity. • The Bi 5 O 7 Br/BiOBr showed tight contact and superior electron-hole separation rate. • The photocatalytic mechanism of Bi 5 O 7 Br/BiOBr was proposed. BiOBr-based composite photocatalysts had attracted extensive attention for efficient photocatalytic degradation aqueous organic pollutants in the past decade. However, the catalysis ability of photocatalyst is greatly limited by their intrinsic high recombination rate of photo-generated charge carriers. Herein, we solve this problem by constructing a novel 2D/3D Bi 5 O 7 Br/BiOBr heterojunction photocatalyst that was prepared via one-step facile hydrolysis process. The pure Bi 5 O 7 Br and pure BiOBr photocatalysts were also obtained by only adjusting the pH value of the mixed solution. The obtained products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), optical and electric property analysis and etc. The results suggested that 2D Bi 5 O 7 Br nanosheets tightly attached to the surface of BiOBr 3D structure with nanoflakes self-assembled microsphere, which could increase the transfer and separation efficiency of photogenerated charges. Furthermore, the 2D/3D Bi 5 O 7 Br/BiOBr heterojunction exhibited superior visible light photocatalytic performance for carbamazepine (CBZ) degradation than pure BiOBr and pure Bi 5 O 7 Br, which owing to the enhanced separation of photoinduced electrons and holes. At last, the underlying photocatalytic mechanism is elucidated based on the band structure and radical scavenging experiments. This work provided a feasible design idea to one-step construct 2D/3D nanocomposite for pharmaceutical wastewater purification. [ABSTRACT FROM AUTHOR]

[Display omitted] • The approach resulted in enhanced nitrate removal efficiency of 67 % for the actual wastewater. • The approach resulted in the continuous release of Fe2+ and Fe3+ ions from the Fe0. • The approach increased in (Nitrospira , Hydrogenophaga , Hyphomicrobium , Sphingobium , Thermus , and Meiothermus). • The approach increased enzymes associated with nitrate metabolism (narB, narG, narH, narI, nirA, nasB, and nasC). This study aimed to investigate the effectiveness of combining zero-valent iron (Fe0) with an electric-magnetic field (EMF) with an intensity of 48-mT generated by an alternating current (AC) of 6 V and 50 Hz applied deep within a reactor using actual wastewater obtained from a secondary stage of a wastewater treatment plant (WWTP). The lab-scale experiment was conducted using the UMSR reactor, maintaining a controlled temperature of 25 ± 2 °C and a hydraulic retention time (HRT) of 5-hour, with a dissolved oxygen (DO) level below 1.5 mg/L. Fine Fe0 particles with a size of ≤ 0.3 µm were added into the reactor at a concentration of 3 g/L. The actual wastewater had an approximate nitrate nitrogen (NO 3 –-N) concentration of 30 ± 2 mg/L, and the substrate mass ratio of carbon to nitrogen (C:N) was at 1:1. The results examined the performance of the EMF-Fe0 system in terms of nitrate removal efficiency and the enrichment of denitrifying bacteria, achieving a nitrate removal rate of 67 % with an effluent NO 3 –-N concentration of 10 mg/L and a chemical oxygen demand (COD) concentration of 11.8 mg/L at removal rate of 60 %. Illumina sequencing revealed various enriched denitrifying bacteria after coupling EMF with Fe0, including autotrophic Nitrospira (NOB) at 4 %, denitrification bacteria like Hydrogenophaga at 1.3 %, Hyphomicrobium at 1 %, and Sphingobium at 5 %, along with thermophilic bacteria Thermus at 1.1 % and Meiothermus at 3.5 %. PICRUSt predicted bacterial functions and analyzed interactions, while KEGG and GO analyses linked nitrogen removal pathways to specific species, genes, and enzymes in the EMF-Fe0 system. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel amorphous FeOOH modified light-switchable OVs BiOBr was prepared. • The amorphous FeOOH and light-induced OVs work in tandem to realize the charges directed flow. • The FeOOH/BiOBr exhibited excellent photocatalytic oxygen evolution activity. Directing the transfer of photoinduced charges to various reaction sites through catalyst design plays crucial roles in enhancing photocatalytic oxygen evolution. Herein, we used a facile alcoholysis method to synthesize amorphous FeOOH modified light-switchable oxygen vacancies BiOBr, which exhibited outstanding photocatalytic oxygen evolution activity. Density functional theory calculations, photoelectronchemical tests and kelvin probe force microscopy revealed that FeOOH overlayer acts as the hole storage layer, while oxygen vacancies (OVs) provided a number of electron trap centers. Benefiting from this synergistic effect, the photogenerated charges showed an outstanding directional transfer performance, which greatly prolong the lifetime of the photo-induced charge carriers. Moreover, as a cocatalyst for water oxidation, FeOOH can effectively lower the kinetics barriers and provide more active sites for oxygen evolution reaction. Therefore, under simulated sunlight irradiation, the 2%FeOOH/BiOBr photocatalyst demonstrated remarkable photocatalytic activity towards oxygen evolution, achieving a rate of 284.34 μmol·g−1·h−1, which is around 1.71 folds than pure BiOBr. Finally, the possible reaction mechanism has also been discussed. This work has provided valuable insights and inspiration for the effective design and optimization of BiOBr-based catalysts, which play a critical role in facilitating efficient directional transfer of photogenerated charges. [ABSTRACT FROM AUTHOR]

• Bi 3 O 4 Br/Ti 3 C 2 Schottky junction with efficient charge transfer was prepared. • The effect of charge transfer on active species generation was discussed. • The Bi 3 O 4 Br/Ti 3 C 2 exhibited excellent photocatalytic degradation activity of bisphenol A. Enhanced photocatalytic active species generation is an important strategy for tuning its visible-light photocatalytic activity, which is highly related to the separation and transfer of photogenerated charge carriers. In this study, we successfully prepared a novel Bi 3 O 4 Br/Ti 3 C 2 two-dimensional/two-dimensional (2D/2D) Schottky junction with special interfacial charge transfer channel via in-situ growth of Bi 3 O 4 Br on the surface of ultrathin Ti 3 C 2. The relevant characterization results indicated that Bi 3 O 4 Br/Ti 3 C 2 had a stable structure and tight interface binding, which shortened the distance of charge transfer, promoted the separation of photogenerated electron-hole pairs, and then enhanced the generation of active species. Therefore, the optimized photodegradation activity and TOC removal efficiency of Bi 3 O 4 Br/Ti 3 C 2 on Bisphenol A (BPA) could reach 91.26% and 70.97% within 60 min visible-light irradiation, respectively. Furthermore, intermediate products and BPA degradation pathways were determined. This work provides a new protocol for the construction of 2D/2D heterojunction photocatalytic systems and regulating photocatalytic active species generation by electronic effective transporting. [ABSTRACT FROM AUTHOR]

[Display omitted] • WO 3 -CuFe 2 O 4 Z-scheme catalyst was constructed. • Quinoline removal was realized by persulfate-assisted photocatalytic process. • Photogenerated holes and ·OH were the main reactive species. • Degradation mechanism and pathways of quinoline were explored. Quinoline is a kind of organic pollutant difficult to be biodegraded, for which the photocatalysis technology is a commonly used removal method, but the degradation performance still needs to be improved. In this work, the WO 3 -CuFe 2 O 4 Z-scheme system was constructed, and the persulfate (PS)-assisted photocatalytic degradation of quinoline with WO 3 -CuFe 2 O 4 by adding persulfate in the photocatalytic systems was studied. The effects of different systems and key parameters such as catalyst dosage, PS concentration and initial pH value on the degradation efficiency of quinoline were investigated. With the addition of persulfate, the degradation efficiency of quinoline increased from 24.3% to 100% in 150 min, under the condition of [PS] = 3 mmol/L, [catalyst] = 3 g/L, temperature = 25 ± 2 °C, and pH = 9. And the WO 3 -CuFe 2 O 4 catalyst showed excellent reusability according to the result of 5-cycle repeated experiment. The possible degradation mechanism was studied by the quenching test and the identification of intermediates and products, which indicated the degradation of quinoline in WO 3 -CuFe 2 O 4 /VIS/PS system was realized via denitrification, dehydrogenation, hydroxylation and ring breaking processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel unipolar pulse potential oscillation (UPPO) system was proposed. • A novel HKUST-1(C)@CoAl LDH film was successfully prepared. • HKUST-1(C)@CoAl LDH film was successfully used for the separation of DS−. • HKUST-1(C)@CoAl LDH film exhibited a high DS− adsorption quantity of 733.84 mg g−1. • The selectivity factors for DS− to other anions varied between 11.67 and 13.28. A carbonized HKUST-1@CoAl layered double hydroxide (HKUST-1(C)@CoAl LDH) film with a three-dimensional (3D) porous structurewas successfully prepared on the copper mesh by using a two-step electrochemical deposition method, and applied in a novel unipolar pulse potential oscillation (UPPO) system for selective separation of dilute dodecyl sulfonate ions (DS−). In the HKUST-1(C)@CoAl LDH film, the CoAl LDH was served as a separating layer to improve the selectivity for DS− ions with the HKUST-1(C) as a storage layer to increase the adsorption amount of DS− ions. As a result, the 3D HKUST-1(C)@CoAl LDH film coated electrode showed excellent selectivity toward DS− ions with a high adsorption capacity of 733.84 mg g−1 and favorable electrochemical stability. More importantly, it is found that such a novel UPPO system can effectively reduce the influence of co-existing anions on the adsorption of DS− ions and accelerate the transport of DS− ions in the film by the periodic potential oscillation, which is expected to be used for the selective separation of DS− ions from practical wastewater. [ABSTRACT FROM AUTHOR]

• In situ synthesis of 2D/2D Bi 24 O 31 Br 10 /Bi 3 O 4 Br heterojunction. • The obtained samples demonstrated excellent visible light activity and stability. • The photocatalytic mechanism and formation mechanism was proposed. In situ synthesized 2D/2D heterojunctions often exhibit a more homogeneous mixture and stronger interface interaction, thereby providing higher interfacial charge transfer and larger interface contact area compared with 0D/2D and 1D/2D heterojunctions. Herein, novel 2D/2D Bi 24 O 31 Br 10 /Bi 3 O 4 Br heterojunctions with a "nanosheet-on-ribbon" hierarchical structure were fabricated via in situ reorganization of original elements in a hydrothermal process, and this method was accomplished through the intervention of NH 3 ·H 2 O. The Bi 24 O 31 Br 10 /Bi 3 O 4 Br heterojunctions exhibit outstanding visible light activity than pure Bi 3 O 4 Br and Bi 24 O 31 Br 10 , reaching photodegradation efficiency of 85% for sulfamethoxazole in 180 min and removal rate of 32.5% for NO in 30 min. Crystalline phases, optical absorption properties, morphologies, microstructures, and band structures were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, differential reflectance spectroscopy, valence band X-ray photoemission spectroscopy, Mott–Schottky methods, density functional theory, photoluminescence spectroscopy, photocurrent analysis, and electrochemical impedance spectroscopy. The superior photocatalytic activity could be ascribed to the special structure and interface interaction between Bi 3 O 4 Br and Bi 24 O 31 Br 10 , thereby enhancing surface-active sites, prolonging light absorption, and promoting charge separation capability during the photocatalytic reaction. The formation mechanism of Bi 24 O 31 Br 10 /Bi 3 O 4 Br heterojunctions was proposed, and NH 3 •H 2 O was not only a pH adjuster but also a structure-controlling agent. This work provides a reference for in situ synthesis of multifunctional 2D/2D photocatalytic nanocomposites. [ABSTRACT FROM AUTHOR]