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1.
Food Chem ; 461: 140762, 2024 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-39153370

RESUMO

In the present paper, carbon cloth (CC) as a flexible substrate was modified by molybdenum carbide nanospheres (Mo2C NSs @CC) by the drop-coating method to develop a sensitive electrochemical platform for detecting caffeic acid. The uniform Mo2C NSs were prepared via an easy route followed by pyrolyzing the precursor of the Mo-polydopamine (Mo-PDA) NSs. The Mo2C NSs were characterized and analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy/energy dispersive X-ray spectroscopy (FE-SEM/EDS), Raman spectroscopy (RS), and electrochemical methods. CC not only gave a flexible feature to the sensor but also provided a larger surface area for Mo2C NSs. Meanwhile, the excellent conductivity and large electroactive specific surface area of Mo2C NSs exhibited excellent electrocatalytic performance for caffeic acid determination. The developed sensor showed high sensitivity and selectivity, good reproducibility, and long-term stability with a limit of detection (LOD) and a wide linear range of 0.001 µM (S/N = 3) and 0.01-50 µM, respectively. In addition, the Mo2C NSs @CC sensor showed a promising application prospect for the detection of caffeic acid in green and black tea samples, indicating its importance in food safety and the food industry.


Assuntos
Ácidos Cafeicos , Carbono , Técnicas Eletroquímicas , Molibdênio , Nanosferas , Chá , Ácidos Cafeicos/análise , Ácidos Cafeicos/química , Chá/química , Técnicas Eletroquímicas/instrumentação , Nanosferas/química , Carbono/química , Molibdênio/química , Limite de Detecção , Contaminação de Alimentos/análise , Camellia sinensis/química
2.
J Colloid Interface Sci ; 675: 150-191, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38968635

RESUMO

Photocatalysis is a promising sustainable technology to remove organic pollution and convert solar energy into chemical energy. Titanium dioxide has drawn extensive attention in this field owing to its high activity under UV light, good chemical stability, large availability, low price and low toxicity. However, the poor quantum efficiency derived from fast electron/hole recombination, the limited utilization of sunlight, and a weak reducing ability still hinder its practical application. Among the modification strategies of TiO2 to enhance its performance, the construction of heterojunctions with other semiconductors is a powerful and versatile way to maximise the separation of photogenerated charge carriers and steer their transport toward enhanced efficiency and selectivity. Here, the research progress and current status of TiO2 modification are reviewed, focusing on heterojunctions. A rapid evolution of the understanding of the different charge transfer mechanisms is witnessed from traditional type II to the recently conceptualised S-scheme. Particular attention is paid to different synthetic approaches and interface engineering methods designed to improve and control the interfacial charge transfer, and several cases of TiO2 heterostructures with metal oxides, metal sulfides and carbon nitride are discussed. The application hotspots of TiO2-based photocatalysts are summarized, including hydrogen generation by water splitting, solar fuel production by CO2 conversion, and the degradation of organic water pollutants. Hints about less studied and emerging processes are also provided. Finally, the main issues and challenges related to the sustainability and scalability of photocatalytic technologies in view of their commercialization are highlighted, outlining future directions of development.

3.
J Environ Manage ; 366: 121890, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39029170

RESUMO

In today's world, the development of an efficient water treatment strategy requires a prospective approach for the production of active and stable photocatalysts. The construction of heterojunctions with different semiconductors is a promising procedure for improving photocatalytic performances. In the present research, binary CeO2-x/BiCrO3 photocatalysts were synthesized using a hydrothermal route preceded by a calcination step. The CeO2-x/BiCrO3 (15%) photocatalyst proved its unique performance of 29.3, 11.4, 11.7, and 23.0 times better than CeO2 for photodegradation of respectively tetracycline hydrochloride (TCH), metronidazole (MET), azithromycin (AZM), and cephalexin (CPN), as antibiotic pollutants, upon visible light. The effective photocatalytic ability, which was caused by the impressive suppression of charge carriers, can be understood by the developed S-scheme mechanism. Moreover, the lower resistance of CeO2-x/BiCrO3 (15%) compared to CeO2, CeO2-x, and BiCrO3 against the charges transfer was another confirmation for boosted photocatalytic performance of the CeO2-x/BiCrO3 (15%) nanocomposite. Ultimately, the boosted activity, repeated utilization for five runs, and biocompatibility confirmation of the purified solution through pinto bean cultivation exhibited that CeO2-x/BiCrO3 photocatalysts could have the promising capability for detoxification of polluted water.


Assuntos
Antibacterianos , Luz , Catálise , Antibacterianos/química , Poluentes Químicos da Água/química , Cério/química , Fotólise
4.
Chemosphere ; 362: 142583, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38866342

RESUMO

In this work, the hydrophobic polyethersulfone (PES) membrane was modified by incorporating Ti3AlCN MAX phase. Synthesis of Ti3AlCN MAX phase was performed using the reactive sintering method. The scanning electron microscopy (SEM) images showed a 3D compressed layered morphology for the synthesized MAX phase. The Ti3AlCN MAX phase was added to the casting solution, and the mixed-matrix membranes were fabricated by the non-solvent induced phase inversion method. The performance and antifouling features of bare and modified membranes were explored by pure water flux, flux recovery ratio (FRR), and fouling resistance parameters. Through the modification of membranes by introducing the Ti3AlCN MAX phase, the enhancement of these features was observed, in which the membrane containing 1 wt% of MAX phase showed 17.7 L/m2.h.bar of permeability and 98.6% for FRR. Also, the separation efficiency of all membranes was evaluated by rejecting organic and inorganic pollutants. The Ti3AlCN MAX membranes could reject 96%, 95%, and 88% of reactive blue 50, Rose Bengal, and azithromycin antibiotics, respectively, as well as 98%, 80%, 86%, and 36% of Pb2+, As5+, Na2SO4, and NaCl, respectively. Finally, the outcomes indicated the Ti3AlCN MAX phase was an excellent and efficient novel additive for modifying the PES membrane.


Assuntos
Membranas Artificiais , Polímeros , Sulfonas , Titânio , Poluentes Químicos da Água , Sulfonas/química , Polímeros/química , Titânio/química , Poluentes Químicos da Água/química , Interações Hidrofóbicas e Hidrofílicas , Permeabilidade , Purificação da Água/métodos
5.
Sci Total Environ ; 929: 172189, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38583624

RESUMO

This study explores the incorporation of Nb2AlC and Mo3AlC2 MAX phases, known for their nano-layered structure, into polyether sulfone (PES) membranes to enhance their antifouling and permeability properties for pathogen microorganism filtration against bovine serum albumin (BSA) and Escherichia coli (E. coli). The composite membranes were characterized for their structural and morphological properties, and their performance in mitigating biofouling was evaluated. The structural characterizations have been performed for all the prepared MAX phases and corresponding composite membranes. The antioxidant ability of Nb2AlC and Mo3AlC2 MAX phases was defined by the DPPH radical scavenging assay, and the highest antioxidant ability was found to be 59.35 %, while 53.69 % scavenging potential was recorded at 100 mg/L. The percentage scavenging ability was raised with an increase in concentrations. The antimicrobial properties of MAX phases, evaluated as the minimum inhibitory concentration, were stated against several pathogen microorganisms. The tested compounds of Nb2AlC and Mo3AlC2 composites containing MAX phases exhibited excellent chemical nuclease activity, and it was determined that Nb2AlC caused double strand DNA cleavage activity while Mo3AlC2 induced the complete fragmentation of the DNA molecule. Biofilm inhibition of Nb2AlC and Mo3AlC2 MAX phases was studied against Staphylococcus aureus, and Pseudomonas aeruginosa and the maximum biofilm inhibition of Nb2AlC and Mo3AlC2 MAX phases was found to be 77.15 % and 69.07 % against S. aureus and also 69.74 % and 65.01 % against P. aeruginosa. Furthermore, Nb2AlC and Mo3AlC2 MAX phases demonstrated excellent E. coli growth inhibition of 100 % at 125 and 250 mg/L.


Assuntos
Incrustação Biológica , Escherichia coli , Membranas Artificiais , Polímeros , Sulfonas , Incrustação Biológica/prevenção & controle , Sulfonas/farmacologia , Sulfonas/química , Polímeros/farmacologia , Escherichia coli/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Filtração
6.
Sci Rep ; 14(1): 9833, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38684695

RESUMO

Supercapacitors and water splitting cells have recently played a key role in offering green energy through converting renewable sources into electricity. Perovskite-type electrocatalysts such as BaTiO3, have been well-known for their ability to efficiently split water and serve as supercapacitors due to their high electrocatalytic activity. In this study, BaTiO3, Al-doped BaTiO3, Ce-doped BaTiO3, and Al-Ce co-doped BaTiO3 nanofibers were fabricated via a two-step hydrothermal method, which were then characterized and compared for their electrocatalytic performance. Based on the obtained results, Al-Ce co-doped BaTiO3 electrode exhibited a high capacitance of 224.18 Fg-1 at a scan rate of 10 mVs-1, high durability during over the 1000 CV cycles and 2000 charge-discharge cycles, proving effective energy storage properties. Additionally, the onset potentials for OER and HER processes were 11 and - 174 mV vs. RHE, respectively, demonstrating the high activity of the Al-Ce co-doped BaTiO3 electrode. Moreover, in overall water splitting, the amount of the overpotential was 0.820 mV at 10 mAcm-2, which confirmed the excellent efficiency of the electrode. Hence, the remarkable electrocatalytic performance of the Al-Ce co-doped BaTiO3 electrode make it a promising candidate for renewable energy technologies owing to its high conductivity and fast charge transfer.

7.
Environ Res ; 252(Pt 2): 118838, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38570124

RESUMO

Herein, Ce-doped CoFe layered double hydroxide (LDH), noted as CoCeFe ternary LDH, was prepared using the co-precipitation route. Prosperous synthesis of CoFe LDH and successful partial replacement of iron cations with cerium cations in CoCeFe ternary LDH were confirmed by X-ray diffraction patterns, energy-dispersive X-ray spectroscopy, and elemental dot-mapping images. Nanosheet morphology was recognized for both CoFe LDH and CoCeFe ternary LDH from scanning electron microscopy and transmission electron microscopy micrographs. In the following, a dispersive solid phase extraction (DSPE) method was developed using the synthesized CoCeFe ternary LDH as a sorbent for extracting perfluorooctanesulfonic acid (PFOS) from wastewater samples. For the selective analysis of PFOS, high-performance liquid chromatography-tandem mass spectroscopy (HPLC-MS/MS) in multiple reaction monitoring mode was used. Analytical parameters such as the limit of detection equal to 0.02 µg/L, with a linear range of 0.05-300 µg/L, the limit of quantification equal to 0.05 µg/L, and an enrichment factor equal to 23.3 were achieved for PFOS at the optimized condition (sorbent: 5 mg of CoCeFe ternary LDH, eluent type and volume: 150 µL mobile phase, pH: 3, adsorption time: 3 min, and desorption time: 5 min). The developed strategy for the analysis of PFOS was tested in real wastewater samples, including copper mine and petrochemical wastewater. The amount of analytes in real samples was calculated using the standard addition method, and good relative recovery in the range of 86%-105% was obtained. The main novelty of this research is the application of CoCeFe ternary LDH to extract the PFOS from wastewater using the DSPE method for determination by HPLC-MS/MS.


Assuntos
Ácidos Alcanossulfônicos , Cério , Cobalto , Fluorocarbonos , Hidróxidos , Ferro , Espectrometria de Massas em Tandem , Poluentes Químicos da Água , Ácidos Alcanossulfônicos/análise , Ácidos Alcanossulfônicos/química , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas em Tandem/métodos , Fluorocarbonos/análise , Fluorocarbonos/química , Hidróxidos/química , Cobalto/análise , Cobalto/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Cério/química , Ferro/química , Ferro/análise , Extração em Fase Sólida/métodos , Águas Residuárias/química , Águas Residuárias/análise , Espectrometria de Massa com Cromatografia Líquida
8.
Artigo em Inglês | MEDLINE | ID: mdl-38604807

RESUMO

Concerted efforts have been made in recent years to find solutions to water and wastewater treatment challenges and eliminate the difficulties associated with treatment methods. Various techniques are used to ensure the recycling and reuse of water resources. Owing to their excellent chemical, physical, and biological properties, nanomaterials play an important role when integrated into water/wastewater treatment technologies. Black phosphorus (BP) is a potential nanomaterial candidate for water and wastewater treatment, especially its monolayer 2D derivative called phosphorene. Phosphorene offers relative adjustability in its direct bandgap, high charge carrier mobility, and improved in-plane anisotropy compared to the most extensively studied 2D nanomaterials. In this study, we examined the physical and chemical characteristics and synthetic processes of BP and phosphorene. We provide an overview of the latest advancements in the main applications of BP and phosphorene in water/wastewater treatment, which are categorized as photocatalytic, adsorption, and membrane filtration processes. Additionally, we explore the existing difficulties in the integration of BP and phosphorene into water/wastewater treatment technologies and prospects for future research in this field. In summary, this review highlights the ongoing necessity for significant research efforts on the integration of BP and phosphorene in water and wastewater applications.

9.
Inorg Chem ; 63(15): 6957-6971, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38576059

RESUMO

Photocatalytic N2 conversion to NH3 is a green, sustainable pathway with renewable energy sources and carbon neutrality. In this research, ternary TiO2 QDs/TiO2 OVs/Cu5FeS4 nanocomposites were prepared by an easy and affordable procedure and utilized to produce clean ammonia energy without a sacrificial agent. The amount of produced green ammonia by the optimum nanocomposite achieved was 17,274 µmol L-1 g-1, which was approximately 20.9, 6.48, 4.45, 2.26, and 1.45 times higher than those of commercial TiO2, TiO2 QDs, TiO2 OVs, Cu5FeS4, and TiO2 QDs/TiO2 OVs photocatalysts, respectively. Lattice compatibility through the developed homojunction within TiO2 QDs/TiO2 OVs and the integration of Cu5FeS4 nanoparticles led to the establishment of a double S-scheme homo/heterojunction system, which improved the photocatalytic activity by maintaining electrons and holes with high oxidation and reduction power and greatly reduced the recombination of charges, which led to the acceleration of charge transfer and migration. Besides, the promoted surface area compared to the pure components, introducing oxygen vacancies, and reducing the particle size boosted the photocatalytic N2 conversion to NH3. The results of this research are a basis for the rational design of homojunction/heterojunction visible-light-responsive systems for photocatalytic nitrogen fixation reactions.

10.
Langmuir ; 40(16): 8503-8519, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38608275

RESUMO

Today, cleaning the environment using photocatalytic technology is one of the main research activities. In this study, carbon dots (C-dots) were anchored on oxygen-vacancy-enriched TiO2 quantum dots (QDs)/TiO2 oxygen vacancies (OVs) using a facile procedure. The resultant ternary TiO2 QDs/TiO2 OVs/C-dots photocatalysts with a quantum dot size of almost 4.55 nm were used for detoxification of aqueous solutions containing four antibiotics and three organic dyes as well as inactivation of two pathogenic bacteria, including Escherichia coli and Staphylococcus aureus, upon visible light. The degradation constant of tetracycline over the optimized TiO2 QDs/TiO2 OVs/C-dots nanocomposite reached 714 × 10-4 min-1, which was 17.3, 12.1, and 2.92 times higher than TiO2 QDs, TiO2 OVs, and TQDs/TOVs (1:1) materials, respectively. Effective separation of electron-hole pairs between TiO2 QDs and TiO2 OVs counterparts through decorated C-dots by an established S-scheme system was the main reason for boosted photocatalytic activity. With regard to the facile growth of wheat and lentil seeds in the treated solutions, it is hoped that the TiO2 QDs/TiO2 OVs/C-dots nanocomposite with significant stability could be used to clean up wastewaters.

11.
J Colloid Interface Sci ; 663: 1035-1051, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38452545

RESUMO

Herein, for the first time, we reported the synthesis of a novel Z-scheme CoxNi1-xTiO3/CdS (x = 0.5) heterojunction photocatalyst and the investigation of its visible-light-driven photocatalytic performance toward degradation of methylene blue (MB). The developed photocatalyst was structurally characterized by applying X-Ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), differential reflectance spectroscopy (DRS), and photoluminescence (PL) techniques. The results indicated the formation of a highly porous structure with improved visible light adsorption capacity, favorable for the catalytic activity. At an optimum condition of 10 mg/L of MB and 300 mg/L of catalyst, the ternary photocatalyst demonstrated a MB removal efficiency of 99 % after 75 min of the treatment process. The radical trapping experiments unveiled that hydroxyl and superoxide radicals were two main reactive species formed under visible light, while the valance holes possessed an insignificant role. The synergetic impact of the CoxNi1-xTiO3 (x = 0.5) and CdS on the photodegradation of MB over the as-prepared CoxNi1-xTiO3/CdS (x = 0.5) photocatalyst through Z-scheme photocatalysis was indicated by the results of the mechanism studies. The percentage impact of the treatment time, MB concentration, the ratio of CoxNi1-xTiO3/CdS (x = 0.5), and the dosage of catalyst using analysis of the CCD modeling was obtained as 47.04, 16.67, 7.22 and 0.87 %, respectively. Furthermore, the as-synthesized photocatalyst possessed high recyclability and photostability with only a 3 % decline in activity after four repetitive cycles.

12.
ACS Appl Mater Interfaces ; 16(8): 10508-10521, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38365188

RESUMO

The potential of blended loose nanofiltration membranes (LNMs) to fractionate dyes and inorganic salts in textile wastewater has become a focus of attention in recent years. In this research work, we fabricated LNMs based on polysulfone (PSf) membranes blended with l-histidine amino acid-functionalized Mo2Ga2C MAX phase (His-MAX). Scanning electron microscopy (SEM), atomic force microscopy (AFM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), contact angle, ζ-potential, porosity, and pore size analyses were employed to characterize the LNMs. Blending 0.75 wt % of His-MAX additive with the PSf tailored the LNM's features by making it more water-friendly, increasing its porosity, enlarging its pores, and making its surface smoother. The pure water flux of 127.6 L/m2 h was achieved by LNM containing 0.75 wt % His-MAX, which was 2.5 times greater than the bare one. The mentioned LNM displayed a flux recovery ratio (FRR) of 68.27 and 98.57, 98.31, and 99.7% rejections for Direct red 23, Acid brown 75, and Reactive blue 21 solutions (100 mg/L), respectively. The 0.75 wt % His-MAX LNM could reject 99.1% of dye and 11.5% of salt while maintaining an FRR of 91.19% after four cycles of filtering a binary mixture solution containing Reactive blue 21 and Na2SO4. These findings highlight the potential of the fabricated LNM for desalinating dye solutions.

13.
Mikrochim Acta ; 191(3): 152, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38388755

RESUMO

The successful synthesis of La-doped CoFe LDH@rGO nanocomposite is reported combining the advantages of LDH and rGO and shows promising performances in electrochemical sensors. The structure of the obtained nanocomposite was investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction pattern (XRD), and field emission scanning electron microscope images (FE-SEM). Then, it was directly utilized to construct a carbon paste electrode (CPE) for urea detection. The electrochemical performance of the sensor was evaluated by various electrochemical methods. The La-CoFe LDH@rGO electrode exhibited excellent electrocatalytic properties, including a wide linear working range of 0.001-23.5 mM, very high sensitivity of 1.07 ± 0.023 µA µM-1 cm-2, a low detection limit of 0.33 ± 0.11 µM, and rapid response time of 5 s towards urea detection at the working potential of 0.4 V. Furthermore, the sensor displayed a high selectivity in different matrices, appropriate reproducibility, and long shelf life without activity loss during 3 months of storage under ambient conditions. Further tests were performed on serum and milk samples to confirm the capability of the proposed sensor for practical applications, demonstrating a reasonable recovery of 94.8 to 102% with an RSD value below 3%. Consequently, the synergistic effect of each component led to the good electrocatalytic activity of the modified electrode towards urea.

14.
Ultrason Sonochem ; 102: 106740, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38171194

RESUMO

The health of all living organisms is greatly influenced by the quality of the water. Therefore, developing cost-effective, eco-friendly, and easily accessible methods is desperately needed to meet the high global demand for clean water. Recently, nanozyme-based dye degradation methods have been promising for the remediation of water pollution. In this work, peroxidase-mimic Co3O4/TiO2 nanocomposite was synthesized and characterized for its size, morphology, and crystalline structure. Colorimetric assay results showed that the peroxidase-like activity of the Co3O4/TiO2 nanocomposite was considerably enhanced compared to the pure Co3O4 NPs and TiO2 NPs. Besides excellent enzyme-mimic activity, the higher sonophotocatalytic dye degradation capability of the nanocomposite after immobilization on zeolite (Co3O4/TiO2@Ze) was also demonstrated. Under optimal conditions (pH = 5.0, 25 °C), 0.1 g/L of catalyst was able to degrade 100 % of methylene blue (MB) with 600 µM in the presence of 30 µM H2O2 within 12 min. GC/MS analysis and toxicity studies revealed less toxic metabolite production after treatment of MB with sonophotocatalytic Co3O4/TiO2@Ze. Modeling of MB degradation using artificial neural networks (ANN) with a 5:6:1 topology was successfully performed, and the results confirmed the fitness of theoretical and experimental outputs according to the calculated correlation coefficient values. The prepared nanocomposite could thus be used as a promising and highly effective catalyst for the removal of organic dyes from polluted water.


Assuntos
Cobalto , Poluentes Ambientais , Nanocompostos , Óxidos , Zeolitas , Zeolitas/química , Poluentes Ambientais/análise , Peróxido de Hidrogênio/análise , Peroxidases , Nanocompostos/química , Água , Redes Neurais de Computação
15.
Sci Rep ; 14(1): 975, 2024 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-38200201

RESUMO

Layered double hydroxides (LDHs), regarding their physical and structural properties, have different and wide applications industry and their increasing use may raise ecological and human health concerns. However, the potential toxicity mechanisms of LDHs in different organisms are still unclear. In the present work, after synthesizing of ZnFe-SO4 LDH and studying of its characterization by XRD, FT-IR, SEM, EDX-mapping, TEM and Raman, its toxicity in Tetradesmus obliquus was evaluated. According to experimental results, the growth of the algae and content of photosynthetic pigments were significantly decreased after treatment with 100 mg/L of ZnFe-SO4 LDH. The high dose exposure to the LDH also inhibited the activity of SOD and POD enzymes, possibly due to the LDH- catalyzed reactive oxygen species production. In addition, lipid peroxidation and the content of phenolic compounds, as no-enzymatic antioxidants were increased by enhancement of the LDH concentration. The rise of phenol, flavonoids and MDA contents could be regarded as some manifestations and responses to the toxic effects of the contaminant in the algae cells. The results provided a better understanding of the undesirable effects and toxicity of LDHs in aquatic organisms.


Assuntos
Clorofíceas , Microalgas , Humanos , Espectroscopia de Infravermelho com Transformada de Fourier , Aconselhamento , Hidróxidos/toxicidade , Fenóis
16.
RSC Adv ; 14(2): 1195-1206, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38174270

RESUMO

Excessive use of antibiotics can lead to an increase in antibiotic-resistant bacteria, which makes it a serious health threat. Therefore, developing new materials with antibacterial activity, such as nanozymes, has gained considerable attention. Reactive oxygen species (ROS) produced by nanozymes have rapid and effective antibacterial efficacy. Here, histidine (His) modified ZnCr layered double hydroxide (LDH) was synthesized inspired by the natural enzyme, and the enzyme-like activity of His/ZnCr-LDH was tested using a colorimetric method. Then, we developed an acid-enhanced antibacterial method based on the high peroxidase-like activity of His/ZnCr-LDH, and its ROS-generating capability in the presence of glucose oxidase (GOx) and glucose (Glu) as a source of hydrogen peroxide (H2O2). Gluconic acid (GA), the main product of the GOx reaction, provides an acidic environment and promotes ROS generation. The mentioned strategy shows high antibacterial activity at a low minimum inhibitory concentration (MIC) which represents the potential of His/ZnCr-LDH for effective bacterial elimination (3.5 µg mL-1 for S. aureus and 6 µg mL-1 for E. coli). In addition, animal experiments illustrated that the His/ZnCr-LDH can successfully boost the curing of infected wounds. The outcomes indicate that amino acid modified LDHs offer a new strategy for effective bacterial removal in different medical applications.

17.
ACS Omega ; 8(48): 45474-45482, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-38075831

RESUMO

Volatile organic compounds (VOCs) are among the most potential pollutant groups that cause air quality degradation because of their toxic effects on human health. Although catalytic oxidation is an effective method for VOC removal, further studies are required to develop more efficient and affordable catalysts. In this study, cerium (Ce) was doped into a CuFe-layered material (Ce-CuFe) to improve the catalytic oxidation efficiencies of N,N-dimethylacetamide (DMAC) and o-xylene. The synthesized catalyst was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analysis. XRD analysis confirmed the successful doping of Ce atoms into the CuFe-layered structure, while in the SEM and TEM images the catalyst appeared as uniformly distributed two-dimensional plate-like particles. The catalytic oxidation performance of the Ce-CuFe was investigated at six temperatures between 200 and 450 °C and three space velocities in the range of 31000-155000 mLh-1g-1 for the oxidation of DMAC and o-xylene, which functioned as polar and nonpolar solvents, respectively. At 200 °C, the Ce-CuFe catalyst performed 50% greater when oxidizing o-xylene while exhibiting a DMAC oxidation efficiency that was 42% greater than that achieved using undoped CuFe. The Ce-CuFe could remove DMAC and o-xylene with an efficiency higher than 95% at 450 °C. Furthermore, Ce-doped CuFe exhibited high resistance against moisture and outstanding reusability performance with only a 5.6% efficiency loss after nine reuse cycles. Overall, the incorporation of Ce into a CuFe-layered material is a promising strategy for the oxidation of various VOCs.

18.
J Biol Eng ; 17(1): 66, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37907952

RESUMO

Montmorillonite (MMt) is extensively applied as an efficient drug-carrier in designing drug delivery systems (DDS) due to its high specific surface area to load drugs. Modification of MMt via iron (Fe) blending can thus be a desirable method to improve its biocompatibility. Herein, magnetic nano-carriers involving the magnetic MMt (mMMt) core surrounded by chitosan (Chito) as a biopolymer and hyaluronic acid (HA) were prepared. To coat the mMMt fabricated through the coprecipitation of the Fe3+/Fe2+ ions in the presence of MMt, the acquired mMMt as the core was then treated with the Chito/HA solution to induce the cross-linked Chito/HA as the shell (namely, the Chito/HA-mMMt). The transmission electron microscopy (TEM) results accordingly revealed the existence of the mMMt inside the Chito/HA solution. Curcumin (CUR) and ciprofloxacin (CIP) were further employed as two model drugs. The CUR and CIP release from the Chito/HA-mMMt subsequently occurred in a sustained manner and pH-dependently. Additionally, an upsurge in the CUR and CIP release by applying an external magnetic field was observed. Thus, the prepared Chito/HA-mMMt hydrogels promise an outstanding potential performance in terms of expanding novel pH-dependent DDS with a sustained release behavior. The scratch assay of the given hydrogels also confirms their applications for wound healing.

19.
Chemosphere ; 344: 140309, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37797897

RESUMO

In this study, considering the serious problem of lack of fresh water worldwide and the effectiveness of reverse osmosis (RO) membranes in water purification, we prepared improved RO membranes with two-dimensional quasi-MXene nanosheets. In this study, the MAX phase with the chemical formula of Ti2AlN was prepared through the reactive sintering route. Prosperous preparation of the MAX phase with the hexagonal crystalline structure was approved by an X-ray diffraction pattern. Compacted sheets morphology was recognized for the prepared MAX phase from transmittance electron microscopy and scanning electron microscopy micrographs. Then, Ti2NTx quasi-MXene nanosheets were prepared by selective ultrasonic-assisted exfoliation of the MAX phase. Polyamide (PA) thin-layer composite RO membranes with different weight percentages of Ti2NTx quasi-MXene were fabricated by the interfacial polymerization (IP) method. The addition of ultrasonic-assisted prepared quasi-MXene creates numerous and coherent nanochannels on the surface of the membrane. The optimum membrane with 0.01 wt% of quasi-MXene showed the highest pure water flux of 31.9 L m-2. h-1 with an improved salt rejection of 98.2%. Therefore, these nanosheets showed that they can partially solve the trade-off between water permeability and salt rejection, which is a serious challenge in RO membranes. Also, the membranes containing quasi-MXene showed good resistance against fouling by humic acid. This research can be a scalable development in making high-performance membranes.


Assuntos
Incrustação Biológica , Nylons , Osmose , Nylons/química , Incrustação Biológica/prevenção & controle , Titânio , Água/química
20.
Chemosphere ; 340: 139817, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37586485

RESUMO

In Electro-Fenton (EF) processes, the use of iron as a catalyst under acidic conditions results in increased costs and potential secondary pollution. To address these issues, we developed a CuFeV layered double hydroxide (LDH) coating on graphite felt (GF) (CuFeV LDH@GF) that offers an effective performance across a broad pH range without causing metal pollution. The CuFeV LDH@GF cathode exhibited a good oxygen reduction performance, high stability, and an efficient removal of levofloxacin (LEV) over a wide pH range (pH = 3-10). The simultaneous presence of Cu2+/Cu3+, Fe2+/Fe3+, and V4+/V5+ redox pairs played a crucial role in facilitating interfacial electron transfer, thereby enhancing the production and subsequent activation of H2O2 within the system. The apparent rate constant (kapp) of LEV removal under neutral conditions with the CuFeV LDH@GF electrode was more than twice that of the raw GF electrode. This improvement can be attributed to the CuFeV LDH coating, which increased the generation of hydroxyl radicals (•OH) from 0.64 to 1.27 mM. Importantly, the CuFeV LDH@GF electrode maintained its efficiency and stability even after 10 reuse cycles. Additionally, GC-MS analyses revealed the degradation of intermediate compounds, which included cyclic and aliphatic compounds. This study provides significant insights into the synergistic effects of trimetallic LDHs, contributing to the development of high-performance cathodes.


Assuntos
Grafite , Poluentes Químicos da Água , Levofloxacino , Peróxido de Hidrogênio/química , Oxirredução , Eletrodos , Grafite/química , Hidróxidos
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