Tetracycline Research Articles

Enhanced photocatalytic degradation of organic pollutants by randomly oriented 2D SnS2 nanostructures

Abstract In this study, we present a bottom-up solvothermal technique using tin tetrachloride pentahydrate (SnCl4.5H2O) and thioacetamide as precursors to synthesize SnS2 nanostructures. Different solvents including isopropyl alcohol, ethanol, and ethylene glycol were used in the reaction to enhance the photodegradation efficiency of organic pollutants, Methylene Blue (MB), and Tetracycline (TC) in an aqueous medium under simulated solar light irradiation. The SnS2 nanostructures synthesized with these solvents were characterized using various structural, morphological, and optical techniques, including XRD, RAMAN, FESEM, XPS, UV–Vis, and Brunauer–Emmett–Teller analysis. The choice of solvent was found to significantly affect the structural, morphological, and optical properties of the SnS2 nanostructures. Notably, the sample synthesized with ethanol as the solvent displayed a unique morphology, enhanced light-harvesting ability, efficient charge carrier separation, and a larger specific surface area, all of which contributed to its superior photocatalytic activity. This sample achieved 99.9% degradation of MB and 95% degradation of TC within 20 and 40 minutes, respectively. The kinetic analysis revealed maximum rate constant (k) values of 0.15242 min-1 for MB and 0.06095 min-1 for TC, as determined by the pseudo-first-order kinetic model. We also discuss the plausible mechanism involving visible light-induced electron-hole pairs that generate reactive species, leading to the mineralization of dyes into H2O, CO2, and other gaseous products. The synthesized SnS2 nanostructures demonstrate significant potential for enhanced photocatalytic activity in organic pollutant degradation, underscoring their promise in addressing water pollution challenges.

A Novel BiOBr/CAU-17 Composite with Enhanced Photo-Catalytic Performance for Dye Degradation and Removal of Tetracycline Antibiotic Under Visible Light.

In order to improve the low specific surface area and high recombinant light generation carriers of BiOBr, loading BiOBr onto suitable Metal Organic Frameworks (MOFs) is an effective strategy to unleash its efficient visible light response and intrinsic catalytic activity. In this study, using classic MOF CAU-17 as a precursor, using a straightforward co-precipitation technique, four BiOBr/CAU-17 composites with distinct MOF contents values BCAU-1, BCAU-2, BC, AU-3, and BCAU-4 were created, and their photo-catalytic characteristics were examined. The BCAU-2 composite exhibited much higher photo-catalytic degradation efficiency for Rhodamine B (RhB) and Tetracycline (TC) than the pristine materials, counter compositions, and early reported materials. XRD, SEM, TEM, XPS, and EDX results revealed the strong synergistic photo-catalytic effect of BiOBr and CAU-17. The photocatalytic degradation of TC was significantly enhanced by the BiOBr bimetal modification, with the 2 wt.% BiOBr/CAU-17 nanocomposite achieving an 87.2 % degradation of TC and 82 % Total Organic Carbon (TOC) removal within 60 min. The high photo-degradation efficiency of BCAU-2 composite should be attributed to the efficient transfer of photo-generated carriers at interfaces and the synergistic effect between BiOBr/CAU-17. Furthermore, the experiments on the capture of the active species proved that the main active free radicals involved in the degradation of RhB and TC are attributed to the photo-induced holes h+ and ⋅ O2 - under visible light. The catalyst's efficacy is corroborated by the outcomes of photoluminescence spectroscopy and photo current response. This study offers a new understanding for the design of green synthesis schemes for photo-catalytic dye degradation and removal of certain antibiotics from the aquatic environment.

Copper-based photocatalysts with natural organic ligands for efficient removal of tetracycline under visible light

The excessive use of broad-spectrum antibiotics, such as tetracycline, presents a significant challenge to human survival and development. Oxygen vacancies (OVs) metal-organic framework (MOF) materials were synthesized using natural organic acids (L-malic acid, L-aspartic acid, and L-asparagine) with similar structures but different charge densities, along with copper as the metal linking agent. The presence of oxygen vacancies in the catalyst provides abundant active sites for photocatalytic reactions. The employment of flexible straight-chain organic ligands devoid of rigid polycyclic rings, combined with the incorporation of different substituents to induce variations in charge density, the resulting catalysts exhibit distinct photocatalytic activities under visible light. Density functional theory calculations confirm that L-asparagine exhibits the largest electron density difference, and the Cu-based MOF (Cu-ASU) synthesized as an organic ligand exhibits the highest photocatalytic activity under visible light excitation. The catalyst displayed remarkable photocatalytic activity against tetracycline antibiotics under identical conditions (with removal rates of 93.5 % for tetracycline, 81.4 % for terramycin, and 95.6 % for chloramphenicol hydrochloride). This provides a novel approach for the design and synthesis of photocatalysts for the removal of antibiotics from water.

Niosome-loaded Tet-Amp against S. aureus, K. pneumoniae, and P. aeruginosa.

Biofilm-associated disorders contribute to elevated morbidity and death rates among patients. We propose synthesizing niosomal structures containing the antibiotics tetracycline and ampicillin ((Tet/Amp)-Nio) and investigating their impact on standard strains of S. aureus, K. pneumoniae, and P. aeruginosa. The antibacterial and anti-biofilm effects of synthesized niosomes against standard pathogenic bacterial strains were studied, and also its cytotoxic activity was investigated against human foreskin fibroblast (HFF) cell line. The optimal formulation (F2) had an average particle size of 196.90 ± 4.57nm, a PDI of 0.223 ± 0.013, a Zeta-potential of -19.25 ± 1.19 mV, a %EE of 70.92 ± 1.75% for Tet and 58.34 ± 1.85% for Amp, and a %Release rate of 49.34 ± 1.78% for Tet and 62.67 ± 1.19% for Amp. The release of Tet and Amp drugs over 48h was 47% and 61%, respectively, from the (Tet/Amp)-Nio formulation. Also, our findings demonstrated that the Tet/Amp)-Nio have potent antibacterial, anti-biofilm, and lower cytotoxic activity compared to the Tet + Amp. In addition, (Tet/Amp)-Nio can upregulate the expression level of matrix metallopeptidase 2 (MMP2) and matrix metallopeptidase 9 (MMP9) genes, which shows their great activity in the wound healing process. The findings of the current investigation suggest that (Tet/Amp)-Nio enhances its antibacterial and antibiofilm effects against S. aureus, P. aeruginosa, and K. pneumoniae isolates. These formulations may serve as a novel approach for targeted drug delivery.

Regulation of the Built‐In Electric Fields of MIL‐125(Ti)@Ti‐Ce‐MOF Yolk‐Shell Z‐Scheme Heterojunctions via Ligand Defects Toward Optimized Photocatalytic Performances

AbstractThe controllable formation of a built‐in electric field (IEF) can effectively separate photogenerated electrons and holes and optimize the band structure of a material, thus improving its photocatalytic performance. Here, a novel type of defective metal‐organic framework (MOF), i.e., an MIL‐125(Ti)@Ti‐Ce‐MOF yolk‐shell Z‐scheme heterojunction, is synthesized using a simple ion‐etching‐coupled reconstruction method. By controlling the concentration of ligand defects within the MOF heterojunction, the strength of the IEF within the heterojunction can be effectively regulated. Moreover, the experimental and theoretical results demonstrated that ligand defects within the Z‐scheme heterojunction structure can enhance the efficiency of photogenerated carrier separation and improve the transport capacity by regulating the IEF. The photocatalytic tetracycline (TC) degradation performance of the resultant MIL‐125(Ti)@Ti‐Ce‐MOF yolk‐shell heterojunction is ≈52.5‐ and 5.5‐fold higher than those of Ti‐Ce‐MOF and MIL‐125(Ti), respectively, indicating the efficient spatial charge separation due to the enhanced IEF. This study reveals the precise control of the IEF over the MIL‐125(Ti)@Ti‐Ce‐MOF yolk‐shell Z‐scheme heterojunction, elucidating the relationship between the IEF and ligand defect concentration and promoting the photocatalytic performances of MOF@MOF‐based catalysts via density functional theory and related experiments.

Synergistic effect of 2D covalent organic frameworks confined 0D carbon quantum dots film: Toward molecularly imprinted cathodic photoelectrochemical platform for detection of tetracycline

The development of high photoactive cathode materials combined with the formation of a stable interface are considered important factors for the selective and sensitive photoelectrochemical (PEC) detection of tetracycline (TC). Along these lines, in this work, a novel type II heterostructure composed of two-dimensional (2D) covalent organic frameworks confined to zero-dimensional (0D) carbon quantum dots (CDs/COFs) film was successfully synthesized using the rapid in-situ polymerization method at room temperature. The PEC signal of CDs/COFs was significantly amplified by improving the light absorption and electron transfer capabilities. Furthermore, a cathodic molecularly imprinted PEC sensor (MIP-PEC) for the detection of TC was constructed through fast in-situ Ultraviolet (UV) photopolymerization on the electrode. Finally, a “turn-off” PEC cathodic signal was achieved based on the selective recognition of the imprinted cavity and the mechanism of steric hindrance increase. Under optimal conditions, the proposed sensor demonstrated a wide linear relationship with TC in the concentration range of 5.00 × 10−12–1.00 × 10−5 M, with a detection limit as low as 6.00 × 10−13 M. Meanwhile, excellent stability, selectivity, reproducibility, and applicability in real river samples was recorded. Our work provides an effective and rapid in situ construction method for fabricating highly photoactive cathode heterojunctions and uniform stable selective MIP-PEC sensing interfaces, yielding accurate antibiotics detection in the environment.

Repurposing expired metformin to fluorescent carbon quantum dots for ratiometric and color tonality visual detection of tetracycline with greenness evaluation

Repurposing expired drugs is highly significant as it prevents the accumulation of pharmaceutical wastes, optimizes resource usage, and reduces environmental harm. Metformin, used for type II diabetes, lowers blood sugar via decreasing liver glucose production and increasing muscle insulin sensitivity. However, the growing number of expired tablets annually necessitates a strategic approach for repurposing or reusing these tablets. Herein, we develop a simple hydrothermal approach for converting expired metformin to valuable fluorescent carbon quantum dots (m-CQDs) with sizes smaller than 10 nm. The m-CQDs displayed a blue emission at 420 nm when excited at 350 nm. Interestingly, when tetracycline (TC) was added, the blue emission diminished, and a greenish-yellow emission emerged at 530 nm. This emission tunning was the resulting of combination of inner filter effect and aggregation induced emission. Leveraging this dynamic emission tunning, we developed both ratiometric-based fluorescence and color tonality-based visual detection methods for detecting TC in pharmaceuticals and wastewater. More importantly, three assessment tools, ComplexMoGAPI, AGREE, and BAGI were used to evaluate the environmental sustainability of the proposed analytical method. The evaluation confirmed the sustainability of the method and the alignment with the greenness guidelines for analytical methods.

Influence of decades-long irrigation with secondary treated wastewater on soil microbial diversity, resistome dynamics, and antibiotrophy development

In arid and semi-arid regions, the use of treated wastewater (TWW) for irrigation is gaining ground to alleviate pressure on natural water sources. Despite said treatment, the existing methods fail to eliminate potentially dangerous contaminants. As such, this study assessed the impact of long-term TWW irrigation (5 and 25 years) on soil physicochemical properties and bacterial resistance to heavy metals (Pb, Cu, Cd) and antibiotics (tetracycline and amoxicillin). The results revealed heightened salinity and conductivity and reduced pH in irrigated soils. TWW induces harmful effects by reducing microbial density and size, leading to the disappearance of sensitive populations. Conversely, resilient populations, which mainly utilize antibiotics as a carbon source, have adapted. Metagenomic 16S amplicon sequencing analysis demonstrated a shift, notably reducing Actinobacteria, Bacteroidetes, and Firmicutes while increasing Acidobacteriota and Patescibacteria in treated soils. Operational Taxonomic Units affiliated with either Halomonadacea, or Saccharimonadacea and Vicinamibacteracea, were defined as indicators of the absence or presence of TWW contamination, respectively. We conclude that TWW irrigation significantly increases bacterial resistance to heavy metals, whereas the impact of antibiotics is nuanced, with antibiotrophy leveraging lower concentrations in treated soils.

Construction of Co-Modified MXene/PES Catalytic Membrane for Effective Separation and Degradation of Tetracycline Antibiotics in Aqueous Solutions

The application of antibiotics has advanced modern medicine significantly. However, the abuse and discharge of antibiotics have led to substantial antibiotic residues in water, posing great harm to natural organisms and humans. To address the problem of antibiotic degradation, this study developed a novel catalytic membrane by depositing Co catalysts onto MXene nanosheets and fabricating the polyethersulfone composite (Co@MXene/PES) using vacuum-assisted self-assembly. The dual role of MXene as both a carrier for Co atoms and an enhancer of interlayer spacing led to improved flux and catalytic degradation capabilities of the membrane. Experimental results confirmed that the Co@MXene/PES membrane effectively degraded antibiotics through peroxymonosulfate activation, achieving up to 95.51% degradation at a cobalt concentration of 0.01 mg/mL. The membrane demonstrated excellent antibacterial properties, minimal flux loss after repeated use, and robust anti-fouling performance, making it a promising solution for efficient antibiotic removal and stable water treatment.

Investigating antimicrobial resistance genes in probiotic products for companion animals

IntroductionOne of the greatest challenges of our time is antimicrobial resistance, which could become the leading cause of death globally within a few decades. In the context of One Health, it is in the common interest to mitigate the global spread of antimicrobial resistance by seeking alternative solutions, alongside appropriate drug selection and responsible use. Probiotics offer a potential avenue to reduce antibiotic usage; however, there is a scarcity of research that examines commercial products in terms of carrying antimicrobial resistance genes (ARGs) involved in resistance development through microbial vectors.MethodsOur study investigated 10 commercially available probiotic products for cats and dogs. Initially, we conducted phenotypic testing through determination of minimum inhibitory concentration (MIC) for antibiotics important in animal and public health. Subsequently, we performed next-generation sequencing (NGS) of the products to elucidate the genetic background behind the decrease in phenotypic sensitivity.ResultsIn total, 19 types of ARGs were identified, with 57.9% being found on plasmids, and in two cases, carriage as mobile genetic elements were found. One of the genes identified was the APH(3′)-Ia gene, capable of inactivating aminoglycoside antibiotics through phosphotransferase enzyme production regulation, while the other was the tetS gene, capable of conferring reduced sensitivity to tetracycline antibiotics through target protection.DiscussionOur findings underscore the importance of approaching antimicrobial resistance investigations from a broader perspective. We suggest that further studies in this area are justified and raise questions regarding the need to extend legally required studies on probiotic products from their use in economic livestock to their use in companion animals.

Iron–Cobalt Bimetallic Metal–Organic Framework-Derived Carbon Materials Activate PMS to Degrade Tetracycline Hydrochloride in Water

Organic pollutants entering water bodies lead to severe water pollution, posing a threat to human health. The activation of persulfate advanced oxidation processes using carbon materials derived from MOFs as substrates can efficiently treat wastewater contaminated with organic pollutants. This research uses NH2-MIL-101(Fe) as a substrate, doped with Fe2+ and Co2+, to prepare Fe/Co-CNs through a one-step carbonization method. The surface morphology, pore structure, and chemical composition of Fe/Co-CNs were investigated using characterization techniques such as XRD, SEM, TEM, XPS, FT-IR, BET, and Raman. A comparative study was conducted on the performance of catalysts with different Fe/Co ratios in activating PMS for the degradation of organic pollutants, as well as the effects of various influencing factors (the dosage of Fe/Co-CNs, the amount of peroxymonosulfate (PMS), the initial pH of the solution, the TC concentration, and inorganic anions) on the catalyst’s activation of persulfate for TC degradation. Through radical quenching experiments and post-degradation XPS analysis, the active radicals in the FeCo-CNs/PMS system were investigated to explain the possible mechanism of TC degradation in the Fe/Co-CNs/PMS system. The results indicate that Fe/Co-CNs-2 (with a Co2+ doping amount of 20%) achieves a degradation rate of 93.34% for TC (tetracycline hydrochloride) within 30 min when activating PMS, outperforming other Co2+ doping amounts. In addition, singlet oxygen (1O2) is the main reactive species in the reaction system.

Highly Efficient Sunlight‐Driven Photocatalytic Activity of Cu‐Doped BiOBr/g‐C3N4 Nanocomposite via Z‐Scheme Design

AbstractPharmaceutical pollutants introduce highly intricate compounds into the environment due to extensive structural and functional alterations resulting in adverse health effects on organisms. Herein, a novel nanocomposite is designed comprising Cu‐doped BiOBr nanoflakes and g‐C3N4 to form a dual absorber based on the organic‐inorganic electronic interface for photocatalytic degradation of tetracycline (TC). With incorporating Cu in BiOBr and compositing with g‐C3N4, the band gap decreased from 2.74 eV to 2.36 eV for BiOBr:Cu/g‐C3N4, and also light harvesting ability increased. The investigation into the degradation rate considered factors such as pH, TC concentration, photocatalyst dosage, and irradiation time, resulting in a TC degradation efficiency of 98 % within 60 min. In the prepared nanocomposite, photo‐generated electrons of BiOBr can recombine via Cu atoms as a mediator with holes in the valence band of g‐C3N4 due to their band structure position which leads to improved electron/hole separation and enhanced photocatalytic activity. The predominant active species involved in the degradation process were found to be superoxide radicals. Additionally, the photocatalyst exhibited excellent stability, retaining 88 % of its photocatalytic activity after four cycles.

MIL-125-PDI/ZnIn2S4 Inorganic-Organic S-Scheme Heterojunction With Hierarchical Hollow Nanodisc Structure for Efficient Hydrogen Evolution from Antibiotic Wastewater Remediation.

Efficient photocatalytic production of H2 from wastewater is expected to address environmental pollution and energy crises effectively. However, the rapid recombination of photoinduced carriers results in low photoconversion efficiency. At present, inorganic-organic S-scheme heterojunction have become a prominent and promising technology. In this study, an organic ligand modified MIL-125-PDI/ZnIn2S4 (ZIS) inorganic-organic S-scheme heterojunction catalyst is designed. ZIS nanosheets are grown on the disc-shaped MIL-125-PDI surface to form a distinctive hollow nanodiscs with hierarchical structure, giving the material an abundance of surface active sites, an optimized electronic structure, and a spatially separated redox surface. Consequently, the optimal 100MIL-125-PDI250/ZIS exhibited high photocatalytic HER of 508.99 µmol g-1 h-1 in Tetracycline hydrochloride (TC-HCl) solution. Meanwhile, the catalyst achieved complete TC-HCl removal and mineralization rate of 66.62% in 4h. Experimental and theoretical calculations corroborate that the staggered band alignment and work function difference between MIL-125-PDI and ZIS induce the formation of a built-in electric field, thus regulating the charge transfer routes and consequently enhancing charge separation efficiency. The possible photocatalytic mechanism is analyzed using liquid chromatography-mass spectrometry (LC-MS), and the toxicities of the degradation products are also evaluated. This work presents a green dual-function strategy for H2 production and antibiotic wastewater recycling.

Flower-Shaped MnFe2O4@MoS2 Nanocomposite Activated H2O2 for Efficient Degradation of Tetracycline: Performance Evaluation, Mechanism and Degradation Pathway

The limited utilization of H2O2 restricts the practical application of heterogeneous Fenton oxidation technology. In this study, the flower-shaped MnFe2O4@MoS2 nanocomposite was prepared by two-step hydrothermal treatment, constructing MnFe2O4@MoS2/H2O2 system for the degradation of tetracycline (TC). Under optimized conditions, MnFe2O4@MoS2/H2O2 system fully degraded 20 mg·L−1 of TC within 60 min, and the corresponding utilization of H2O2 was also as high as 95.7%. Meanwhile, this system not only exhibited excellent cycling stability for the degradation of TC but also had good anti-interference ability against actual water sources, inorganic cations and anions and natural organic compounds. The efficient activation of H2O2 in MnFe2O4@MoS2/H2O2 system mainly relied on the redox cycling of Fe(II)/Fe(III) and Mn(II)/Mn(III) mediated by MoS2; meanwhile, the oxygen vacancies caused by redox cycling also accelerated activation of H2O2, resulting in the production of a large number of active species (·OH, ·O2− and 1O2) for rapid degradation of pollutants. The vulnerable atomic sites of TC were confirmed through theoretical calculation, and four degradation pathways of TC in MnFe2O4@MoS2/H2O2 system were proposed. Finally, the toxicity analysis confirmed that the toxicity of degradation intermediates was developing towards low toxicity. This study provided new insights into the wide application of heterogeneous Fenton systems in wastewater treatment.

Sustainable photodegradation of tetracycline by surface-functionalized carbon nitride: Mechanism insight and toxicity assessment

Here, we report the facile preparation of amino- and vacancies-abundant carbon nitride photocatalyst using acetone as a low-boiling-point solvent and describe its successful performance of environmental purification. As a demonstration of the notion, tetracycline (TC) antibiotic as an emerging aqueous contaminant has been used as a model substrate for assessing the photoactivity of the modified carbon nitride and clarifying its intrinsic mechanism. 96 % of TC can be photocatalytically removed within 30 min, accompanied by a discernible mitigation in ecotoxicological impact. Reactive species, including •OH, •O2-, and photogenerated holes, are considered the critical oxidants. Meanwhile, the possible intermediates and transformation pathways of TC degradation were investigated utilizing the LC-MS technique, the Fukui function, and the T.E.S.T. software. The comprehensive approach furnishes valuable insights for assessing the evolutionary dynamics of tetracycline in an advanced oxidation process (AOP). This study offers a sustainable, cost-effective, and eco-friendly approach to preparing carbon nitride material, which is believed to open an avenue for the facile design of heterogeneous environmental photocatalysts and to provide insights into the various environmental applications.

Efficient Adsorption and Degradation of Tetracycline Hydrochloride Using Metal-Organic Framework-Derived Cobalt-Based Catalysts and Mechanism Insight.

High-performance Co-based catalysts were derived by pyrolysis using synthesized MOFs as self-sacrificial templates. Various catalytic systems were constructed by peroxymonosulfate (PMS) to degrade tetracycline hydrochloride (TC). Adsorption-degradation efficiencies, cycle performance, dynamics, and the adsorption catalytic mechanism of various catalytic systems for TC were studied. The effects of different synthetic solvents, pyrolysis temperatures, and single/bimetallic element compositions on degradation efficiency were innovatively compared. The optimal catalyst and PMS dosage for the experiment were determined to be 10 mg and 0.1 mL, respectively. The results indicated that all catalytic systems could efficiently degrade TC and have a high acid-base resistance. The catalyst activity was significantly influenced by the pyrolysis temperature. The optimum pyrolysis temperatures for Zn@Co-N-C-T, CH3OH@Co-N-C-T, and H2O@Co-N-C-T were 1000, 900 and 900 °C, respectively. More abundant pore structures and active sites were generated in Zn@Co-N-C-1000, exhibiting an excellent TC degradation efficiency and adsorption capacity, achieving 94.73% and 167.564 mg/g, respectively. Meanwhile, the total organic carbon (TOC) of TC (50 mL, 50 mg/L) achieved a removal rate (TOC/TOC0) of 50.28%. Zn@Co-N-C-1000/PMS maintained over 83.27% TC degradation after five cycles. The adsorption mechanism of the catalyst for TC was investigated through the analysis of adsorption kinetics and isotherm models. The quenching test and EPR results indicated that TC was primarily degraded through the nonradical pathway. The efficient degradation of TC is attributed to the rapid electron transfer processes occurring at the two-phase interface and the redox cycling of Co0/Co2+/Co3+. Finally, LC-MS was used to analyze the intermediate products of TC degradation in the Zn@Co-N-C-1000/PMS system, and two degradation pathways were proposed.

Improvement of tetracycline removal using amino acid ionic liquid modified magnetic biochar based on theoretical design

In current research, biochar is widely used to remove antibiotic contamination from the environment. However, original biochar produced through direct pyrolysis has significant limitations in removing antibiotics. In this paper, response surface methodology provided the laudable choice for magnetic poplar biochar (MPBC) considering the synergistic effect of multi-factors as well as the restrictions abundance experiments during the preparation of MPBC. Amino acid ionic liquids (AAILs) are a class of ionic liquids in which amino acids act as the anionic component, combining the tunable properties of ionic liquids with the biocompatibility and functionality of amino acids. To ameliorate adsorption capacity of MPBC, tetra-ethylammonium glycinate ([TEA][Gly]) with the best affinity for tetracycline (TC) were screened from 600 AAILs based on theoretical predictions using the conductor-like screening model for real solvents (COSMO-RS) without extensive experimental. Furthermore, AAILs-modified magnetic biochar (MPBC-AAIL) was synthesized chemically for the first time. Adsorption kinetics, isotherms, and thermodynamic analyses revealed that TC adsorption by both MPBC and MPBC-AAIL is a monolayer, spontaneous, and exothermic chemical process. Moreover, MPBC-AAIL exhibited a maximum adsorption capacity of 305.9 mg·g−1. Meanwhile, MPBC-AAIL maintains superior adsorption performance for TC in different impurity solutions as well as in real water samples. The excellent reusability and selective adsorption capacity of the material demonstrate the superiority of the theoretical based design. The characterization reveals that the adsorption mechanisms include pore filling, π-π interactions, surface complexation, hydrogen bonding, and electrostatic interactions. In addition, theoretical calculations showed that ionic liquid modification altered the adsorption sites between TC and MPBC-AAIL, leading to enhanced adsorption. This comprehensive study introduces an innovative modification of biochar, providing a novel approach to designing biochar composites and promoting their application in the remediation of complex environmental pollution.

Enhanced self-biased photocatalytic fuel cell performance by dual-photoelectrode with novel graphene-based substrate for tetracycline photodegradation and electricity production

In this study, a graphene-based dual-photoelectrode photocatalytic fuel cell (PFC) system, incorporating n-type ZnO photoanode and p-type Cu2O photocathode, has been meticulously designed and fabricated to achieve concurrent organic pollutant decomposition and electricity production. The rGO-ZnO｜rGO-Cu2O PFC system displayed superior photoelectrocatalytic performance, surpassing the comparative FTO-based PFC system. Notably, it achieved power density of 22.23 μW cm−2 maximumly, tetracycline hydrochloride (TCH) degradation efficiency of 74.0 % within 120 min, and exhibited long-term stability. This enhanced performance can give the credit to the larger active areas generated by the in-situ growth of photocatalytic materials in layered microstructure of graphene films, as well as the rapid electron transfer within graphene films. This study underscores the potential application of graphene films as electrode substrate materials, and introduces a strategy for achieving the diversification and optimization of electrode substrate material selection, ultimately facilitating the development of more efficient PFC systems.

Sustainable di-functional stimuli-responsive imprinted nanozymes for reversible colorimetric sensing of tetracycline

Regenerable nanozymes with high catalytic specificity and sustainability may serve as substitutes for naturally occurring enzymes, but their application is hindered by inadequate and nonselective catalytic activity. In this study, we constructed a photo-responsive molecularly imprinted layer on the Fe3O4 nanozyme surface (P-MIPs) using an ATRP method and obtained high-specificity reversible colorimetric sensing of tetracycline (TC). Due to the photo-responsive properties of P-MIPs, the imprinted nanozyme undergoes reversible release and uptake of TC under alternating irradiation at 365/440 nm based on the photo-regulated conformational transformation of the 4-[(4-methacryloyloxy)phenylazo] benzenesulfonic acid (MAPASA) at the polymer receptor sites, which may be confirmed by calculating the electron densities of the trans-/cis-MAPASA forms. Simultaneously, these processes can be visualized through the change in the color of the substrates. Highly specific P-MIPs-based nanozyme also exhibit adequate stability and sustainable catalytic activity after multiple cycles. This method can be used to achieve nanozymes with high selectivity for the enrichment, separation, and detection of hazardous substances and contribute to material sustainability.

Discrimination of tetracycline in water using a fluorescence probe based on UiO-67 Encapsulated with NCDs

The large-scale production and abuse of antibiotics cause environmental pollution, threaten human health, and destroy the ecological balance. Efficient detection of these pollutants has emerged as a prominent topic in current research. In this study, we developed a novel material called UiO-67-NCDs by combining UiO-67 with nitrogen-doped carbon dots (NCDs) for sensing trace amounts of tetracycline (TC) in water. The NCDs were successfully introduced onto UiO-67 by the post-synthesis modification, resulting in a strong blue fluorescence at 445 nm. Thanks to the hydrogen bonding, π-π interactions and the internal filter effect (IFE) between UiO-67 and NCDs, UiO-67-NCDs was capable for TC sensing, exhibiting fluorescence quenching in 10 s with a limit of detection (LOD) of 32.9 nM (0–38 μM). The visual detection capabilities, high sensitivity, rapid detection time, and simplicity of the fluorescent probe make it a promising candidate for antibiotic detection in aqueous environments. This will further stimulate the interest of researchers in the in-depth study of MOFs and quantum dots and their applications in sensing.