Photodegradation Of Tetracycline Research Articles

Interaction and band structure-determined inhibition of negative Cr (VI) and positive Fe (III) for antibiotic photodegradation by nitrogen-doped dissolved black carbon

The influences of the positive Fe3+ and the negative Cr2O72− on the tetracycline (TC) photodegradation by N-doped dissolved black carbon (NDBC) have been investigated in this work. A series of samples (NDBC300, NDBC400 and NDBC500) have been extracted from the corresponding biochar. NDBC400 has the best photodegradation performance (79%) for TC under visible light irradiation. Adding Cr2O72− and Fe3+ can reduces TC photodegradation efficiency into 37% and 53%, respectively. This maybe from that Cr2O72− has stronger interaction with NDBC400 than Fe3+ since it can quench more fluorescence intensity of NDBC400 than Fe3+. Furthermore, Cr2O72− can reduce the steady-state concentration of 3NDBC400*, 1O2 and •OH, whereas Fe3+can just reduce the steady-state concentration of 3NDBC400* and increase the concentration of •OH. This may explain why Cr2O72− has stronger inhibit performance of TC photodegradation by NDBC400 than Fe3+. The band structures of NDBC400, NDBC400-Fe3+ and NDBC400-Cr2O72− are constructed. And the VB of NDBC400-Fe3+ has a stronger ability to produce •OH than NDBC400. In summary, coupling interaction and band structure characterization of NDBC400, NDBC400-Fe3+ and NDBC400-Cr2O72− can explain well why Cr2O72 has stronger inhibition effect than Fe3+ and Fe3+ can increase the concentration of •OH. This work provides a deep insight for the photochemical behavior of dissolved black carbon and the transformation behavior of the co-existed metal ions and antibiotics.

Efficient synthesis of multifunctional α-Fe2O3 QDs/TS-1 as an artificial nanozyme for simultaneous colorimetric detection and photodegradation of tetracyclines

In this study, a multifunctional catalyst was developed innovatively by loading α-Fe2O3 quantum dots (QDs) onto Titanium Silicalite-1 (TS-1), creating an artificial nanozyme capable of simultaneously detecting, adsorbing, and photodegrading tetracyclines (TCs) in water. The catalyst demonstrated a limit of detection (LOD) as low as 19.7 μg/L for oxytetracycline (OTC), 23.1 μg/L for doxycycline (DOX), and 35.9 μg/L for tetracycline (TC). The peroxidase-mimic activity of the nanozyme, which was enhanced by TCs and caused a visible color change in 3,3′,5,5′-tetramethylbenzidine (TMB), was thoroughly investigated using DFT calculations. Additionally, the artificial nanozyme exhibited exceptional adsorption capabilities and photocatalytic activity under solar light irradiation, achieving a total removal rate of about 70 %. The underlying mechanism was also studied. This research provided valuable insights for the scalable production of multifunctional catalysts, thereby advancing the practical application of “integration of diagnosis and treatment” strategies for managing and controlling TCs in the environment.

Zinc indium sulfide coupling with graphitic carbon nitride containing non-intrinsic oxygen vacancies to form Z-scheme heterojunction for boosting photodegradation of tetracycline

A novel graphitic carbon nitride containing non-intrinsic oxygen vacancies (Vo-CN) is interfacial coupling with zinc indium sulfide (ZIS) to form Z-scheme heterojunction (VCZ) for efficient tetracycline (TC) degradation. The TC removal rate by VCZ-1 (mass ratio of Vo-CN: ZIS is 1:20, 0.2 g/L) achieves 99.86 %. VCZ-1 reveals outstanding reusability and stability with an unchanged TC degradation rate after undergoing five cycles. VCZ-1 achieves high-efficiency TC degradation in various water matrices. The experimental and DFT calculations indicate that the built-in electric field drives charges on Vo-CN transfer to ZIS, forming a Z-scheme VCZ-1 heterojunction. The strong electronic coupling effect between Vo-CN and ZIS facilitates charge exchange at the heterojunction interface. Non-intrinsic oxygen vacancies in VCZ, as binding sites for electrons and holes, effectively lower the energy barrier for singlet excitons converting to triplet excitons. The triplet excitons are induced to transfer energies to dissolved oxygen and expedite 1O2 production. 1O2 synergizes with •O2– and •OH to attack O-containing groups and hexatomic rings in TC, inducing demethylation, hydroxylation, dihydroxylation, and ring-opening reactions. Three possible degradation pathways are inferred by UPLC/MS/MS and Fukui index of TC. The ecotoxicity evaluation of intermediate products highlights the benefits of VCZ-1 photocatalytic oxidation in ensuring environmental safety. This work proposes a novel idea for constructing efficient Z-scheme photocatalysts for environmental remediation.

Synergetic enhancement effect of MOF-derived porous ZnO/ Co3O4 cage Z-scheme heterostructure for high-performance photodegradation

Using solar energy for photocatalytic degradation of pollutants is a clean and effective method for treating the increasingly severe problem of environmental pollution. Herein, porous ZnO/Co3O4 cages with improved charge separation ability was designed via a facile ZIF-8@ZIF-67-derived approach for tetracycline (TC) photodegradation. Great photodegradation performance and good stability were achieved. The degradation rate was as high as 97 % within 60 min. The enhancement mechanism of TC photodegradation was investigated. The porous structure of ZnO/Co3O4 produced a number of active sites. The effective utilized spectrum was extended from the ultraviolet to the red region. The presence of two mixed valence states of Cobalt, Co2+ and Co3+, increased the density of defect states and was conducive to the adsorption of TC. The composite had a Z-scheme heterojunction, in which strong oxidative capacity can be maintained, combination of electrons and holes was greatly reduced and efficient charge transfer occurred. This study would give new insights into the design of new photocatalysts with synergetic enhancement effect for TC photodegradation.

Synthesis of Ag/CuS doped mineral magnetite nanocomposite with improved photocatalytic activity against tetracycline and diclofenac pollutants

The contamination of water sources by pharmaceutical pollutants presents significant environmental and health hazards, making the development of effective photocatalytic materials crucial for their removal. This research focuses on the synthesis of a novel Ag/CuS/Fe₃O₄ nanocomposite and its photocatalytic efficiency against tetracycline (TC) and diclofenac contaminants. The nanocomposite was created through a straightforward and scalable precipitation method, integrating silver nanoparticles (AgNPs) and copper sulfide (CuS) into a magnetite framework. Various analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR),ultraviolet–visible spectrophotometry (UV–Vis) and energy-dispersive X-ray spectroscopy (EDS), were employed to characterize the structural and morphological properties of the synthesized material. The photocatalytic activity was tested by degrading tetracycline and diclofenac under visible light. Results indicated a marked improvement in the photocatalytic performance of the Ag/CuS/Fe₃O₄ nanocomposite (98%photodegradation of TC 60 ppm in 30 min) compared to both pure magnetite and CuS/Fe₃O₄. The enhanced photocatalytic efficiency is attributed to the synergistic interaction between AgNPs, CuS, and Fe3O4, which improves light absorption and charge separation, thereby increasing the generation of reactive oxygen species (ROS) and promoting the degradation of the pollutants. The rate constant k of photodegradation was about 0.1 min−1 for catalyst dosages 0.02 g. Also the effect of photocatalyst dose and concentration of TC and pH of solution was tested. The modified photocatalyst was also used for simultaneous photodegradation of TC and diclofenac successfully. This study highlights the potential of the Ag/CuS/Fe₃O₄ nanocomposite as an efficient and reusable photocatalyst for eliminating pharmaceutical pollutants from water.

Copper decorated cuprous oxide–carbon nitride plasmonic p-n heterojunction with high-efficiently charge transfer for photodegradation of tetracycline

In this work, a novel copper decorated cuprous oxide–carbon nitride (Cu@Cu2O-g-C3N4) plasmonic p-n heterojunction was prepared by solvothermal method using pre-synthesized carbon nitride and Cu@Cu2O precursors as raw materials. The morphology observation for the sample exhibits that Cu2O precursor is dispersed from micrometer octahedrons to the particles with the sizes of 20 ∼ 200 nm under action of dimethylformamide, forming a close contact between Cu nanoparticles, Cu2O particles and g-C3N4 stacking flakes. The results of photodegradation shown that 96.4 % of 10 mg·L−1 tetracycline (TC) solution was decomposed within 60 min and degradation rate decreased by 9.2 % after five cycles. Photoelectrochemical characterizations indicated that photocatalytic performance of Cu@Cu2O-g-C3N4 was attributed to high-efficiently charge transfer base on the synergistic effect of heterojunction and plasmon resonance. The formation of p-n type built-in electric field between Cu@Cu2O and g-C3N4 enhances photocatalytic oxidative and reductive ability of the catalyst, and dual coupling effects induced by the localized surface plasmon resonance of Cu nanoparticles promote the amount of photogenerated electrons. This work provides a strategy for preparing efficient p-n heterojunction photocatalysts with plasma coupling effects by reconstructing the junction interface using facile solvothermal method.

Polychloride and benzene ring synergistically boosting photocatalytic degradation and nitrogen fixation performances of carbon nitride

The limited active site exposure, insufficient light absorption and poor charge behavior of carbon nitride (CN) limit its application in environmental remediation and clean energy production. In this study, ultrathin porous CN with enhanced photocatalytic activity was constructed by doping 2,2′,5,5′-Tetrachlorobenzidine (TB) into CN framework. The synergistic effect of polychloride and benzene rings on CN leads to the significant enhancement of range/intensity of visible-light harvest and charge behavior, as well as specific surface area. The optimal sample achieves 100% tetracycline photodegradation efficiency with a rate constant approximately 9 times of pristine CN, and total organic carbon removal efficiency reaches 78.2%. Moreover, photocatalytic ammonia production rate is 7 times of pristine CN. Through active species trapping experiments, ESR, LC-MS, toxicity prediction and DFT calculations, the main active species, degradation pathway, intermediates toxicity and enhanced mechanism of photocatalytic activity are investigated. This work provides a reference for simultaneously regulating the morphology, light absorption and charge behavior of CN-based photocatalyst for addressing environmental and energy concerns.

A novel S-scheme photocatalyst Fe2O3/Bi2O3/g-C3N4 with enhanced visible-light photocatalytic performance for antibiotic degradation and CO2 reduction: RSM-based optimization

The degradation of pollutants and reduction of CO2 to hydrocarbon fuels using photocatalysis is a potential approach to reducing CO2 emissions and decreasing environmental contamination. This study introduces an innovative S-scheme photocatalyst (Fe2O3/Bi2O3/g-C3N4) synthesized through simple methods for the first time. The structural, morphological, and optical properties of the synthesized photocatalysts were comprehensively characterized using XRD, XPS, FTIR, SEM, TEM, HR-TEM, BET, UV–vis DRS, PL, ESR, and mott-Schottky analyses, respectively. The visible light photodegradation of tetracycline (TC) antibiotic and CO2 conversion were carried out in order to evaluate the photocatalytic performance of these synthesized materials. Using the RSM-CCD approach, the influence of key variables on TC degradation were optimized. The results indicated that the optimized photocatalyst (45-FeBiC) exhibited higher photocatalytic performance (99.87 %) compared to other samples via photogenerated •O2−, and •OH. Additionally, four cycle studies verified that the 45-FeBiC nanocomposite had adequate photostability. After 6 h of visible light illumination, the 45-FeBiC catalyst generated 33.84 μmol/g of CO and maintained 96.2 % of its initial photocatalytic activity after 30 h of reaction. The enhanced photocatalytic efficiency of the 45-FeBiC nanocomposite is attributed to the photosensitization effect of 3 wt%-Fe2O3/Bi2O3 on g-C3N4 within the S-scheme photocatalytic framework.

Synergistic effect in ZIF-67/MoS2 entrenched MWCNT photo (electro) catalyst for degradation of tetracycline and alternative to Pt counter electrode in dye-sensitized solar cells

Photocatalytic water purification is an effective environmental protection approach for removing hazardous chemicals in water, besides solar energy conversion is a trustworthy and sustainable choice for the future due to rising energy demands. The present research focus is on synthesis of Metal-Organic Framework (MOF) based composite, Zeolitic Imidazolate Framework-67/Molybdenum Disulfide (ZIF-67/MoS2) entrenched Multi-Walled Carbon Nanotubes (MWCNT) as a catalyst for photodegradation of tetracycline (TC), as well as substitute for Pt counter electrode in Dye-Sensitized Solar Cell (DSSC). The crystalline structure, optical response, shape, porosity, quantum states, and chemical configuration were determined using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-DRS), Photoluminescence spectroscopy (PL), Transmission Electron Microscopy (TEM), Brunauer-Emmett-Teller (BET), and X-ray Photoelectron Spectroscopy (XPS), respectively. The degradation efficiency of ZIF-67/MoS2/MWCNT catalyst under effect of operational parameters namely, photocatalyst dosage, solution pH, coexisting ions, TC concentrations and irradiation time were studied consecutively. ZIF-67/MoS2/MWCNT composite achieved 96.1 % degradation efficiency of TC under white light irradiation. Interestingly, when utilized as a counter electrode in DSSCs, this composite-based electrode delivered the highest Power Conversion Efficiency (PCE) of 3.86 % with a short-circuit current density (JSC) of 7.54 mA cm−2 and open-circuit voltage (VOC) of 0.79 V. The observed enhancement is attributed to lesser peak-to-peak separation (EPP), lower electron lifetime, lower charge transfer resistance (RCT) and higher exchange current density (J0). Based on these findings, ZIF-67 inclusion in MoS2/MWCNT composite is not only an effective catalyst for water treatment but also a good catalyst for I3− reduction in DSSCs.

Synthesis of g-C3N4 decorated with ZIF-8 and CuFe2O4 as a highly efficient and magnetically separable photocatalyst for degradation of tetracycline

In this study, for the first time a magnetically recoverable zeolitic imidazolate framework-8 (ZIF-8) / graphite carbon nitride (g-C3N4)/ cooper ferrite (CuFe2O4) nanocomposite was prepared through a fast and simple wet impregnation procedure. The magnetic behavior of the ZIF-8/g-C3N4/CuFe2O4 heterostructure was used for the easy recovery of the nanocomposite by an external magnet. After studying the structural, crystallinity, magnetic, and photophysical properties of the as-syntesized sample, its application was investigated for the enhanced photodegradation of tetracycline under visible light illumination. The band gap energies for ZIF-8, g-C3N4, and CuFe2O4 were obtained 5.1 eV, 2.8 eV, and 1.3 eV, respectively. After combination of ZIF-8, g-C3N4, and CuFe2O4, the band gap energy was obtained to 2.4 eV, which indicate the improvement of photocatalytic activity of ZIF-8/g-C3N4/CuFe2O4 nanocomposite. Among the as-synthesized photocatalyst samples, the ZIF-8/g-C3N4/CuFe2O4 showed an excellent photocatalytic activity (99.15 %) for degradation of tetracycline within 65 min irradiation of visible light, solution pH of 5 and photocatalyst dosage of 0.75 g/L. The rate constant of the ZIF-8/g-C3N4/CuFe2O4 is almost 13.1, 9.9, and 15.6 times higher than that of ZIF-8, g-C3N4, and CuFe2O4, respectively. The ZIF-8/g-C3N4/CuFe2O4 heterojunction showed the effective degradation activity for four consecutive cycles, which exhibited its excellent reusability and stability. Moreover, the free radical quenching tests confirmed that holes, and hydroxyl radicals were the main reaction species for degradation of tetracycline. Altogether the preparation of novel ZIF-8/g-C3N4/CuFe2O4 provides an promise avenue for the development of high potential magtenticaly photocatalytic systems for sustainable tetracycline production with remarkable efficiencies.

CuS Nanoparticles/MIL-125(Ti) Heterojunction as Photocatalyst for the Photodegradation of Tetracycline

CuS Nanoparticles/MIL-125(Ti) Heterojunction as Photocatalyst for the Photodegradation of Tetracycline

Enhanced light harvesting ability in hollow Pt/TiO2 nanoreactor for boosting tetracycline photodegradation

Utilizing solar energy to decompose tetracycline (TC) is a green strategy to treat wastewater. Herein, a heterogeneous hollow structured TiO2 decorated Pt nanoparticles were successfully designed and synthesized via hard-template approach and photo-deposition process toward TC photodegradation. The Pt nanoparticles loaded on the surface of hollow structured TiO2 can increase the visible light absorption due to the local surface plasmon resonance (LSPR) effect. Furthermore, owing to the tough electron oscillation of the LSPR excitation, the plasmonic hot holes on the surface of Pt nanoparticles can capture the electrons of TiO2, effectively facilitating the separation of photo-excited charge carriers because of the formation of Schottky junction constructed between Pt and TiO2. Combined the natural merits of shorten conveying path of charge carriers and physical structural stability for hollow structure, the optimal Pt/TiO2 hetero-junction hybrid showed superior photocatalytic activity and durability for TC photodegradation with the degradation efficiency of 93.8 ​% after 30 ​min and the rate constant of 0.09196 min−1 under 300 ​W Xe lamp irradiation. This work displays a heterogeneous hybrids catalyst based on eco-friendly metal and semiconductor materials which can be used in the fields including without limitation TC photodegradation.

MOF-derived In2O3/TiO2 S-scheme heterojunction for efficient photocatalytic degradation of tetracycline

It is challenging to engineer a photocatalyst that can degrade antibiotics efficiently. We have successfully developed a series of photocatalysts by annealing In-MOF (BUT-205) with TiO2, namely (a) In2O3/TiO2-I, (b) In2O3/TiO2-II, and (c) In2O3/TiO2-III. These catalysts, particularly In2O3/TiO2-III, exhibited superior efficiency in degrading tetracycline (TC) under visible light. The enhanced photocatalytic performance of In2O3/TiO2-III can be attributed to the formed S-scheme heterojunction, which promoting the separation of electron-hole pairs. The S-scheme heterojunction was confirmed by XPS, in-situ XPS, UV–vis diffuse reflectance spectroscopy, and Mott-Schottky plot, etc. Compared to pure TiO2 and In2O3, the In2O3/TiO2-III demonstrated an 18-fold and 3-fold higher degradation rate constant (k). Various factors affecting the degradation of TC were investigated, including pollutant concentration, catalyst type, solution pH, catalyst dosage, inorganic anions, inorganic cations, and radical species. Photoluminescence (PL) and transient photocurrent density evaluate the separation rate of electron-hole pairs, and EPR experiments (active species trapping) studies confirmed •O2− and h+ as the primary entities in TC photodegradation by In2O3/TiO2-III. HPLC/MS analysis revealed the photocatalytic degradation pathway. The MOF-derived photocatalysts efficiency in TC photoreduction results from the formed S-scheme heterojunction, making it a promising candidate for environmental remediation.

Construction of novel BiOI/CuInS2/ZnO dual S-scheme charge transfer pathway for efficient antibiotic degradation

The present work explored the photocatalytic activity of BiOI–CuInS2–ZnO ternary heterojunction for the photodegradation of the tetracycline (TCl). The bare photocatalysts were prepared via hydrothermal method while the ternary heterojunction was synthesized using simple physical mixing route. The ternary heterojunction of BiOI, CuInS2 and ZnO followed the S-scheme charge transfer pathway exhibiting superior photodegradation ability compared to other synthesized photocatalysts. The attained degradation efficiency of BiOI–CuInS2–ZnO S-scheme ternary heterojunction was 96.75 % within 90 min of light illumination which was much higher than other photocatalysts. Electron spin resonance (ESR) investigations and scavenging experiment indicated that •O2−, and •OH radicals plays an important role in photodegradation of TCl. Furthermore, the structural analysis of synthesized bare photocatalysts was also done via density functional theory (DFT) calculations. The results showed that after the formation of S-scheme heterojunction, the ternary heterojunction showed lower recombination rate (validated via PL analysis) with boosted charge carriers separation rate (confirmed through EIS and TPR analysis) and light absorption ability. This had led to upgradation in photodegradation efficiency of ternary BiOI–CuInS2–ZnO photocatalyst. The reusability test of the photocatalysts confirmed excellent stability of ternary photocatalysts with 90.25 % degradation rate up to five catalytic cycles.

Facile synthesis of magnetic resorcinol–formaldehyde resin Fe3O4@RF-Au composites for enhanced tetracycline photodegradation with simultaneous H2O2 production

Facile synthesis of magnetic resorcinol–formaldehyde resin Fe3O4@RF-Au composites for enhanced tetracycline photodegradation with simultaneous H2O2 production

Synthesis of a novel cost-effective double-ligand Zr-based MOF via an inverted modulator strategy towards enhanced adsorption and photodegradation of tetracycline

Developing visible-light response photocatalysts with high activity and adsorption alongside sustainability is vitally important to environmental restoration. Here, we fabricated a novel metal organic framework (MOF) with cost-effective double-ligands (fumaric acid and 2-aminoterephthalic acid as ligand precursors, denoted as MA-MOF) via a facile solvothermal method. Specifically, crystalline [Zr6O4(OH)4(fumarate)6] (MOF-801) can be only formed with monocarboxylic acids as modulators. Therefore, in the construction of crystalline double-ligand MA-MOF, the absence of monocarboxylic acid modulators successfully prevents the formation of crystalline MOF-801. Instead, the crystalline double-ligand MA-MOF is formed. Properties of MA-MOFs including the surface area, porosity, charge transfer resistance, and energy level position can be adjusted via altering the ratio of ligands. The optimal sample, MA-MOF2 (prepared with a molar ratio of fumaric acid and 2-aminoterephthalic acid being 2:1), shows a total 94.6% removal of tetracycline via adsorption and photodegradation, far exceeding the corresponding single-ligand counterparts. This work proposes an innovative inverted modulator strategy for constructing double-ligand MOFs.

Evaluation of tetracycline photocatalytic degradation using NiFe2O4/CeO2/GO nanocomposite for environmental remediation: In silico molecular docking, antibacterial performance, degradation pathways, and DFT calculations

Graphene-based nanostructures with distinct structural and physicochemical characteristics may be able to photodegrade antibiotics effectively. Herein, this study reports the successful synthesis of NiFe2O4/CeO2/GO nanocomposite (NC) by anchoring NiFe2O4/CeO2 to the surface of GO (Graphene oxide). All state-of-the-art characterization techniques investigated the nanostructure, crystallinity, phonon modes, chemical composition analysis, elemental composition, surface area, magnetic properties, and optical band gap. Hydrothermal approach assisted NiFe2O4/CeO2/GO catalyst showed better charge carrier separation and prompted the tetracycline (TC-HCl) photocatalytic degradation under visible light. Following 90 min of exposure to visible light, NiFe2O4/CeO2/GO nanocomposite demonstrated superior photocatalytic activity, with a TC-HCl degradation rate of 95%. Reasonable mechanisms of tetracycline degradation were proposed where the •OH and •O2- played a leading role based on identified intermediates. Moreover, tetracycline photodegradation intermediates and the optimal pathway were identified using LC-MS spectrometry. This study alsoperformed Density Functional Theory (DFT) calculations for the preparedmaterials to validate the experimental data. In vitro, antibacterial studies were consistent with the molecular docking investigations of the NiFe2O4/CeO2/GO nanocomposite against DNA gyrase and FabI from Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Lastly, the outcomes revealed a new potential for NiFe2O4/CeO2/GO nanocomposite for improved photocatalytic performance, making it a promising photocatalyst for wastewater treatment.

Precise structure-tailoring of multicomponent nanocatalysts enabled by continuous flow-controlled flash nanoprecipitation technique

Nanostructured catalysts with diverse compositions offer an exciting prospect for various catalytic applications. The precise control of nanostructures allows to tune the physicochemical properties of nanocatalysts and improve their performance. However, most preparative methods rely on conventional batch systems, which require tedious procedures and cause low productivity. Herein, we reported a novel engineered flash nanoprecipitation (FNP) technique to synthesize well-structured nanocatalysts in a continuous-flow procedure with intelligent operation and high productivity, in which a series of multicomponent bismuth oxyhalides (BiOClxBr1-x) were demonstrated as the model catalysts. This method was established on the uninterrupted continuous synthesis of BiOClxBr1-x with precisely controlled microstructure by simply altering the flow rate ratio of precursor fluids in the reactor. The computational fluid dynamics (CFD) simulation showed that the automized flow setup could achieve the accurate control over the intensified fluid mixing. Significantly, a volcano relationship between the halogen compositions and catalytic activities toward photodegradation of tetracycline (TC) was observed, which indicated that the structural changes enabled band structure-dependent regulation. The FNP-processed BiOCl0.75Br0.25 possessed a balanced redox ability and light absorption, thus located at the peak of volcano with a five-fold enhancement of intrinsic photocatalytic activity. Overall, this work provides a promising prospect of continuous-flow technique in the engineered manufacturing of the advanced nanomaterials, offering fine-tuning of the nanostructures of materials with low cost and high productivity.

Construction of functionalized In-based metal organic framework/BiOCl1−xIx Z-scheme heterojunction for efficient photocatalytic degradation of tetracycline: Performance and mechanism

The environmental implications of antibiotics have drawn widespread attention. Numerous monomer-based bismuth oxide halide catalysts have been extensively studied to remove tetracycline (TC) from aquatic environments. Integrating bismuth oxide halide composites with In-based metal organic framework (NH2-MIL-68(In)) might potentially serve as a novel strategy. By meticulously adjusting Cl and I within the composite bismuth halide oxide (B-x), a suite of purpose built heterojunctions (NMB-x) were synthesized, which were engineered to facilitate the efficient photodegradation of TC in simulated and actual aquatic environments. The incorporation of Z-scheme heterojunctions yielded a significant enhancement in photocatalytic responsiveness and charge carrier separation. Notably, NMB-0.3 demonstrated remarkable TC removal efficiency of 88.52 ± 3.05%, which is 3.74 times of B-0.3 within 90 min. The apparent quantum yield was also increased from 8.97% (B-0.3) to 19.68% (NMB-0.3). The removal of TC from natural water bodies was also assessed. Moreover, the photocatalyst concentration, assessed using response surface method, was found to show influential factors on TC removal. In addition, density functional theory (DFT) simulations were employed to identify vulnerable sites within TC. Intermediates and pathways in the photodegradation of TC have also been inferred. Furthermore, a comprehensive environmental toxicity assessment of representative intermediates demonstrated that these intermediates exhibited significantly reduced environmental toxicity compared to TC. This study provides a new approach to the design strategy of efficient and environmentally friendly MOF-based photocatalysts.

Fabrication of porous and defect-rich BiOI/MWCNTs photocatalyst by Ar plasma-etching for emerging pollutants degradation

Carbon material modification and defect engineering are indispensable for bolstering the photocatalytic effectiveness of bismuth halide oxide (BiOX). In this study, a novel porous and defect-rich Ar-CB-2 photocatalyst was synthesized for emerging pollutants degradation. Leveraging the interfacial coupling effect of multi-walled carbon nanotubes (MWCNTs), we expanded the absorption spectrum of BiOI nanosheets and significantly suppressed the recombination of charge carriers. Introducing defects via Argon (Ar) plasma-etching further bolstered the adsorption efficacy and electron transfer properties of photocatalyst. In comparison to the pristine BiOI and CB-2, the Ar-CB-2 photocatalyst demonstrated superior photodegradation efficiency, with the first-order reaction rates for the photodegradation of tetracycline (TC) and bisphenol A (BPA) increasing by 2.83 and 4.53 times, respectively. Further probe experiments revealed that the steady-state concentrations of ·O2− and 1O2 in the Ar-CB-2/light system were enhanced by a factor of 1.67 and 1.28 compared to CB-2/light system. This result confirmed that the porous and defect-rich structure of Ar-CB-2 inhibited electron-hole recombination and boosted photocatalyst-oxygen interaction, swiftly transforming O2 into active oxygen species, thus accelerating their production. Furthermore, the possible degradation pathways for TC and BPA in the Ar-CB-2/light system were predicted. Overall, these findings offered a groundbreaking approach to the development of highly effective photocatalysts, capable of swiftly breaking down emerging pollutants.