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1.
Small ; 20(1): e2304580, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37653596

RESUMO

Blue quantum dot light-emitting devices (QLEDs) suffer from fast electroluminescence (EL) loss when under electrical bias. Here, it is identified that the fast EL loss in blue QLEDs is not due to a deterioration in the photoluminescence quantum yield of the quantum dots (QDs), contrary to what is commonly believed, but rather arises primarily from changes in charge injection overtime under the bias that leads to a deterioration in charge balance. Measurements on hole-only and electron-only devices show that hole injection into blue QDs increases over time whereas electron injection decreases. Results also show that the changes are associated with changes in hole and electron trap densities. The results are further verified using QLEDs with blue and red QDs combinations, capacitance versus voltage, and versus time characteristics of the blue QLEDs. The changes in charge injection are also observed to be partially reversible, and therefore using pulsed current instead of constant current bias for driving the blue QLEDs leads to an almost 2.5× longer lifetime at the same initial luminance. This work systematically investigates the origin of blue QLEDs EL loss and provides insights for designing improved blue QDs paving the way for QLEDs technology commercialization.

2.
Small ; 20(6): e2306115, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37775951

RESUMO

The unsatisfactory power conversion efficiency (PCE) and long-term stability of tin perovskite solar cells (TPSCs) restrict its further development as alternatives to lead perovskite solar cells (LPSCs). Considerable research has focused on the negative impacts of O2 and H2 O, while discussions about degradation mechanism in an inert atmosphere remains insufficient. Herein, the light-induced autoxidation of tin perovskite in nitrogen atmosphere is revealed for the first time and the elastic lattice distortion is demonstrated as the crucial role of rapid degradation. The continuous injection of photons induces energy transfer from excited A-site cations to vibrating Sn-I framework, leading to the elastic deformation of perovskite lattice. Consequently, the over distorted Sn-I framework releases free iodine and further oxidizes Sn2+ in the form of molecular iodine. Through an appropriately designed light-dark cyclic test, a remarkable PCE of 14.41% is achieved based on (Cs0.025 (MA0.25 FA0.75 )0.975 ) 0.98 EDA0.01 SnI3 solar cells, which is the record of hybrid triple TPSCs so far. The findings unveil autoxidation as the crux of TPSCs' degradation in an inert atmosphere and suggest the possibility of reinforcing the tin perovskite lattice towards highly efficient and stable TPSCs.

3.
Small ; : e2405171, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39165056

RESUMO

Polyanionic A3V2(PO4)3 (A = Li+, Na+) with open channels have been extensively utilized as cathode materials for aqueous zinc-metal batteries (AZMBs), whereas suffering from severe capacity fading and rapid operation voltage decay during cycling. when used as In this work, it is disclosed that the rapid degradation is induced by an irreversible phase change from electrochemical active Li3V2(PO4)3 to nonactive monoclinic LiZnPO4, as well as active Na3V2(PO4)3 to nonactive rhombic Zn3(PO4)2(H2O)4. Subsequently, a rational dual-cation (Al-Fe) doping strategy is proposed to suppress these detrimental transformations. Such dual-cation doping entails stronger P-O and V-O bonds, thus stabilizing the initial polyanionic structures. Consequently, the optimized member of Li3V1.775Al0.075Fe0.225(PO4)3 (LVAFP) exhibits desirable cycling stability (1000 cycles, 68.5% capacity retention) and notable rate capability (92.1% of the initial capacity at 10 C). Moreover, the dual-cation doping methodology is successfully extended to improve the stability of Na3V2(PO4)3 cathode in aqueous dual-ion batteries, signifying the versatility and feasibility of this strategy. The comprehensive identification of local structural evolution in these polyanions will broaden the scope of designing high-performance alkali-vanadyl-phosphates for multivalent aqueous batteries.

4.
Environ Sci Technol ; 2024 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-39324836

RESUMO

In this study, vacuum ultraviolet (VUV) was first proposed to activate ferrate (Fe(VI)) for degrading micropollutants (e.g., carbamazepine (CBZ)). Results indicated that VUV/Fe(VI) could significantly facilitate the CBZ degradation, and the removal efficiencies of VUV/Fe(VI) were 30.9-83.4% higher than those of Fe(VI) at pH = 7.0-9.0. Correspondingly, the degradation rate constants of VUV/Fe(VI) were 2.3-36.0-fold faster than those of Fe(VI). Free radical quenching and probe experiments revealed that the dominant active species of VUV/Fe(VI) were •OH and Fe(V)/Fe(IV), whose contribution ratios were 43.3 to 48.6% and 48.2 to 46.6%, respectively, at pH = 7.0-9.0. VUV combined with Fe(VI) not only effectively mitigated the weak oxidizing ability of Fe(VI) under alkaline conditions (especially pH = 9.0) but also attenuated the deteriorating effect of background constituents on Fe(VI). In different real waters (tap water, river water, WWTPs effluent), VUV/Fe(VI) retained a remarkably enhanced effect on CBZ degradation compared to Fe(VI). Moreover, VUV/Fe(VI) exhibited outstanding performance in the debasement of CBZ and sulfamethoxazole (SMX), as well as six other micropollutants, displaying broad-spectrum capability in degrading micropollutants. Overall, this study developed a novel oxidation process that was efficient and energy-saving for the rapid removal of micropollutants.

5.
Environ Res ; 243: 117845, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38065383

RESUMO

In this work, the oxidation of gatifloxacin (GAT), fleroxacin (FLE) and enoxacin (ENO) in aqueous solution by ferrate (Fe(VI)) was systemically investigated. Weak alkaline and high oxidant doses were favorable for the reaction. The pseudosecond-order rate constants were 0.18055, 0.29162, and 0.05476 L/(mg·min), and the activation energies were 25.13, 15.25, and 11.30 kJ/mol at pH = 8.00 and n(Fe(VI)):n(GAT) = 30:1, n(Fe(VI)):n(FLE) = 20:1, n(Fe(VI)):n(ENO) = 40:1 and a temperature of 25 °C. The maximum degradation rates of the GAT, FLE and ENO were 96.72%, 98.48% and 94.12%, respectively, well simulated by Response Surface Methodology. During the oxidation, the contribution of hydroxyl radicals (HO•) varied with time, whereas the final contribution was approximately 20% at 30 min. The removal efficiency was inhibited by anions by less than 10%, and cations by less than 25%, and significantly inhibited by high concentrations of humic acid. Moreover, two or three dominant reaction pathways were predicted, and the ring cleavages of quinolone and piperazine were mainly achieved through decarboxylation, demethlation and hydroxylation, and some pathways ended up with monocyclic chemicals, which were harmless to aquatic animals and plants. Theoretical calculations further proved that the reactions between FeO4- and neutral fluoroquinolone antibiotics were the major reactions. This work illustrates that Fe(VI) can efficiently remove fluoroquinolone antibiotics (FQs) in aqueous environments, and the results may contribute to the treatment of wastewater containing trace antibiotics and Fe(VI) chemistry.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Animais , Fluoroquinolonas , Água , Ferro , Oxirredução , Antibacterianos , Poluentes Químicos da Água/análise , Cinética , Purificação da Água/métodos
6.
Environ Res ; 262(Pt 2): 119889, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39216738

RESUMO

Antibiotics with pseudo-persistence in water have been regarded as emerging pollutants, which have obvious biological toxicity even at trace levels. On account of high reactivity, heterogeneous catalytic ozonation has been widely applied to remove antibiotics. Among the heterogeneous catalysts, with well-developed pores and regulable surface defects, carbon-based materials can act as both adsorbents and catalysts. Metal cations, surface hydroxyl (-OH) groups and oxygen vacancies (OVs) serve as primary active sites in metal oxides. However, composites (perovskite, apatite, etc.) with special crystalline structure have more crystallographic planes and abundant active sites. The unsaturated bonds and aromatic rings which have dense structure of the electron cloud are more likely to be attacked by ozone (O3) directly. Sulfonamides (SAs) can be oxidized by O3 directly within a short time due to the structure of activated aromatic rings and double bonds. With the existence of catalysts, almost all antibiotics can attain fair removal effects. The presence of water matrix can greatly influence the removal rate of pollutants via changing the surface properties of catalysts, competing active sites with O3, etc. Correspondingly, the application of diverse heterogeneous catalysts was introduced in details, based on modification including metal/non-metal doping, surface modification and carrier composite. The degradation pathways of SAs, fluoroquinolones (FQNs), tetracyclines (TCs) and ß-lactams were summarized founded on the functional group structures. Furthermore, the effects of water matrix (pH, coexisting ions, organics) for catalytic ozonation were also debated. It is expected to proffer advanced guidance for researchers in catalytic ozonation of antibiotics.

7.
Environ Res ; 257: 119314, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38824988

RESUMO

This study synthesized novel, green, and easily recoverable surface-modified economical catalysts via hydrothermal treatment (HT) successfully, utilizing biogas residue biochar (BRB), a food waste product from anaerobic fermentation, pyrolyzed at 500 °C for 50 min. Using autoclaves, a total of six solutions were prepared, each having 1 g fine-grinded BRB, surficial modified by adding glycerol (GL) (10 or 20 mL) and SDI water (70 or 60 mL), and heated in an oven at 240 °C, 180 °C, and 120 °C for 24 h. Afterward, the catalysts showed the potential for degradation of widely used emerging pollutants like ciprofloxacin. Taking advantage of catalytic surface modification, the catalytic ozonation degradation was more effective than that of a single ozonation. However, under similar conditions, catalyst amount 0.20 g, ozone dose 15 mg L-1, and ciprofloxacin 80 mg L-1, the performance of the 10 mL GL-180 °C catalyst was excellent. It showed a 92.45%-94.41% optimum removal rate in the 8-10 min interval. After five continuous cycles, the 10 mL GL-180 °C catalyst exhibited excellent stability and reusability. XPS, FT-IR, BET, XRD, and SEM before and after the reaction confirmed the successful synthesis and degradation mechanism. A possible degradation pathway was unrevealed based on a liquid chromatography-mass spectrometer (LC-MS) and scavenger test, proving the significant roles of superoxide radicals (O2•-), hydroxyl radicals (•OH), and singlet oxygen (1O2). Further, Electron paramagnetic resonance (EPR) analysis confirmed the presence of active oxygen species. Subsequently, 10 mL GL-180 °C showed promising degradation for the actual water environment, such as groundwater (73.55%) and river water (64.74%). This work provides a valuable economic strategy to convert biogas residue biochar into a low-cost catalyst for organic pollutant decomposition.


Assuntos
Biocombustíveis , Carvão Vegetal , Ciprofloxacina , Ozônio , Poluentes Químicos da Água , Ozônio/química , Carvão Vegetal/química , Ciprofloxacina/química , Catálise , Poluentes Químicos da Água/química , Biocombustíveis/análise
8.
Environ Res ; 258: 119395, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38909944

RESUMO

In this study, we report the development of a novel CuOx(3 wt%)/CoFe2O4 nanocubes (NCs) photocatalyst through simple co-precipitation and wet impregnation methods for the efficient photocatalytic degradation of triclosan (TCS) pollutants. Initially, rod-shaped bare CoFe2O4 was synthesized using a simple co-precipitation technique. Subsequently, CuOx was loaded in various percentages (1, 2, and 3 wt%) onto the surface of bare CoFe2O4 nanorods (NRs) via the wet impregnation method. The synthesized materials were systematically characterized to evaluate their composition, structural and electrical characteristics. The CuOx(3 wt%)/CoFe2O4 NCs photocatalyst exhibited superior photocatalytic degradation efficiency of TCS (89.9%) compared to bare CoFe2O4 NRs (62.1 %), CuOx(1 wt%)/CoFe2O4 (80.1 %), CuOx(2 wt%)/CoFe2O4 (87.0 %) under visible light (VL) irradiation (λ ≥ 420 nm), respectively. This enhanced performance was attributed to the improved separation effectiveness of photogenerated electron (e-) and hole (h+) in CuOx(3 wt%)/CoFe2O4 NCs. Furthermore, the optimized CuOx(3 wt%)/CoFe2O4 NCs exhibited strong stability and reusability in TCS degradation, as demonstrated by three successive cycles. Genetic screening on Caenorhabditis elegans showed that CuOx(3 wt%)/CoFe2O4 NCs reduced ROS-induced oxidative stress during TCS photocatalytic degradation. ROS levels decreased at 30, 60, and 120-min intervals during TCS degradation, accompanied by improved egg hatching rates. Additionally, expression levels of stress-responsible antioxidant proteins like SOD-3GFP and HSP-16.2GFP were significantly normalized. This study demonstrates the efficiency of CuOx(3 wt%)/CoFe2O4 NCs in degrading TCS pollutants, offers insights into toxicity dynamics, and recommends its use for future environmental remediation.


Assuntos
Cobalto , Cobre , Triclosan , Triclosan/química , Triclosan/toxicidade , Animais , Cobre/química , Catálise , Cobalto/química , Compostos Férricos/química , Compostos Férricos/toxicidade , Luz , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/efeitos da radiação , Fotólise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade
9.
Biomed Chromatogr ; 38(1): e5760, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37852619

RESUMO

Duvelisib (DUV) was first approved globally in 2018. An extensive literature search revealed that the differential role of a potential degradation medium in altering the shelf-life of DUV due to its exposure during storage has not been identified till date. Moreover, its degradation impurities and degradation mechanism are not known. In addition, no analytical method has been reported for the quantification of DUV in the presence of its degradation impurities. Therefore, the aim of this study was to identify the impact of different potential degradation media on the stability of DUV, establish the degradation mechanism, and identify its major degradation impurities. The aim was also to establish a stability-indicating analytical method for the quantification of DUV in the presence of its degradation impurities. This study is the first to report the structure of degradation impurities and the step-by-step degradation mechanism of DUV. This information will be useful for the scientific community and manufacturers in optimizing the formulation parameters and/or storage conditions. The validated method can be employed for analysis of stability study and routine quality control samples of newer DUV formulations in pharmaceutical industries. The identified impurities may serve as impurity standards for specifying their limits in the drug after required qualification studies.


Assuntos
Espectrometria de Massa com Cromatografia Líquida , Espectrometria de Massas em Tandem , Cromatografia Líquida , Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Medicamentos , Estabilidade de Medicamentos
10.
Biomed Chromatogr ; 38(1): e5761, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37920143

RESUMO

Selumetinib (SELU) was recently approved by the US Food and Drug Administration (US FDA) in 2020. However, the degradation impurities of SELU have not been characterized or identified to date. The mechanism for impurity formation and the degradation behavior have not been previously studied. This study aims to elucidate the prototypical degradation mechanism of SELU. Furthermore, the degradation impurities have been identified using LC-quadrupole-time-of-flight tandem mass spectrometry and are reported in this article for the first time. In addition, a stability-indicating analytical method (SIAM) has been developed for this drug. Forced degradation studies revealed the degradation of SELU under various stress conditions, including hydrolytic stress (acid and base), oxidative stress, and photolytic stress (ultraviolet and visible). Three degradation impurities were identified. This article presents the first validated SIAM, capable of accurately quantifying SELU in the presence of its degradation impurities. Furthermore, we have proposed the degradation pathway for SELU and its degradation impurities, a first in the field. The developed SIAM can find applications in process development and quality assurance of SELU in both research laboratories and pharmaceutical industries. Moreover, the identified degradation impurities may serve as impurity standards for quality control testing in pharmaceutical industries.


Assuntos
Contaminação de Medicamentos , Espectrometria de Massas em Tandem , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/métodos , Estabilidade de Medicamentos , Cromatografia Líquida/métodos
11.
Ecotoxicol Environ Saf ; 270: 115944, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38184978

RESUMO

Food contaminated by mycotoxins has become a worldwide public problem with political and economic implications. Although a variety of traditional methods have been used to eliminate mycotoxins from agri-foods, the results have been somewhat less than satisfactory. As an emerging non-thermal processing technology, atmospheric cold plasma (ACP) has great potential for food decontamination. Herein, this review mainly presents the degradation efficiency of ACP on mycotoxins in vitro and agri-foods as well as its possible degradation mechanisms. Meanwhile, ACP effects on food quality, factors affecting the degradation efficiency and the toxicity of degradation products are also discussed. According to the literatures, ACP could efficiently degrade many mycotoxins (e.g., aflatoxin, deoxynivalenol, zearalenone, ochratoxin A, fumonisin, and T-2 toxin) both in vitro and various foods (e.g., hazelnut, peanut, maize, rice, wheat, barley, oat flour, and date palm fruit) with little effects on the nutritional and sensory properties of food. The degradation efficacy was dependent on many factors including ACP treatment parameter, working gas, mycotoxin property, and food substrate. The mycotoxin degradation by ACP was mainly attributed to the reactive oxygen and nitrogen species in ACP, which can damage the chemical bonds of mycotoxins, consequently reducing the toxicity of mycotoxins.


Assuntos
Fumonisinas , Micotoxinas , Gases em Plasma , Zearalenona , Micotoxinas/toxicidade , Gases em Plasma/química , Contaminação de Alimentos/análise , Fumonisinas/análise
12.
Pestic Biochem Physiol ; 201: 105858, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38685237

RESUMO

Beta-cypermethrin (ß-CY) residues in food are an important threat to human health. Microorganisms can degrade ß-CY residues during fermentation of fruits and vegetables, while the mechanism is not clear. In this study, a comprehensively investigate of the degradation mechanism of ß-CY in a food microorganism was conducted based on proteomics analysis. The ß-CY degradation bacteria Gordonia alkanivorans GH-1 was derived from fermented Pixian Doubanjiang. Its crude enzyme extract could degrade 77.11% of ß-CY at a concentration of 45 mg/L within 24 h. Proteomics analysis revealed that the ester bond of ß-CY is broken under the action of esterase to produce 3-phenoxy benzoic acid, which was further degraded by oxidoreductase and aromatic degrading enzyme. The up-regulation expression of oxidoreductase and esterase was confirmed by transcriptome and quantitative reverse transcription PCR. Meanwhile, the expression of esterase Est280 in Escherichia coli BL21 (DE3) resulted in a 48.43% enhancement in the degradation efficiency of ß-CY, which confirmed that this enzyme was the key enzyme in the process of ß-CY degradation. This study reveals the degradation mechanism of ß-CY by microorganisms during food fermentation, providing a theoretical basis for the application of food microorganisms in ß-CY residues.


Assuntos
Esterases , Proteômica , Piretrinas , Piretrinas/metabolismo , Esterases/metabolismo , Esterases/genética , Alimentos Fermentados/microbiologia , Fermentação , Escherichia coli/metabolismo , Escherichia coli/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética
13.
Int J Mol Sci ; 25(18)2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39337452

RESUMO

The enantioselective mechanism of the esterase QeH against the two enantiomers of quizalofop-ethyl (QE) has been primitively studied using computational and experimental approaches. However, it is still unclear how the esterase QeH adjusts its conformation to adapt to substrate binding and promote enzyme-substrate interactions in the catalytic kinetics. The equilibrium processes of enzyme-substrate interactions and catalytic dynamics were reproduced by performing independent molecular dynamics (MD) runs on the QeH-(R)/(S)-QE complexes with a newly developed residue-specific force field (RSFF2C). Our results indicated that the benzene ring of the (R)-QE structure can simultaneously form anion-π and cation-π interactions with the side-chain group of Glu328 and Arg384 in the binding cavity of the QeH-(R)-QE complex, resulting in (R)-QE being closer to its catalytic triplet system (Ser78-Lys81-Tyr189) with the distances measured for the hydroxyl oxygen atom of the catalytic Ser78 of QeH and the carbonyl carbon atom of (R)-QE of 7.39 Å, compared to the 8.87 Å for (S)-QE, whereas the (S)-QE structure can only form an anion-π interaction with the side chain of Glu328 in the QeH-(S)-QE complex, being less close to its catalytic site. The computational alanine scanning mutation (CAS) calculations further demonstrated that the π-π stacking interaction between the indole ring of Trp351 and the benzene ring of (R)/(S)-QE contributed a lot to the binding stability of the enzyme-substrate (QeH-(R)/(S)-QE). These results facilitate the understanding of their catalytic processes and provide new theoretical guidance for the directional design of other key enzymes for the initial degradation of aryloxyphenoxypropionate (AOPP) herbicides with higher catalytic efficiencies.


Assuntos
Esterases , Simulação de Dinâmica Molecular , Esterases/química , Esterases/metabolismo , Estereoisomerismo , Especificidade por Substrato , Domínio Catalítico , Cinética
14.
Int J Mol Sci ; 25(2)2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38255887

RESUMO

The effect of the structure of promising antioxidant agents with prospective medical use, i.e., unsubstituted and para-substituted annelated triazinylacetic acid hydrazides, on their melting points, thermal stabilities, pyrolysis and oxidative decomposition stages and the type of volatiles emitted under heating with the use of DSC and TG/DTG/FTIR/QMS methods was evaluated and discussed. The melting point of the investigated compounds increased with an enhanced number of electrons (directly correlated with their molecular weight). Melting enthalpy values were determined and presented for all the studied compounds. The pyrolysis and oxidative decomposition processes of the analysed molecules consisted of several poorly separated stages, which indicated a multi-step course of the decomposition reactions. It was found that the thermal stability of the tested compounds depended on the type of substituent at the para position of the phenyl moiety or its absence. In both atmospheres used (air and helium), the thermal stability increased in relation to R as follows: -CH3 ≤ -OCH3 < -H < -OC2H5. In an inert atmosphere, it was higher by approx. 8-18 °C than in an oxidative atmosphere. The pyrolysis was connected with the emission of NH3, HCN, HNCO, HCONH2, HCHO, CO2, CO and H2O in the case of all the tested compounds, regardless of the substituent attached. In the case of the derivative containing the para-CH3 group, para-toluidine was an additional emitted aromatic product. In turn, emissions of aniline and alcohol (methanol or ethanol) for compounds with the para-OCH3 and para-OC2H5 groups, respectively, were confirmed. In oxidative conditions, the release of NH3, NO, HCN, HNCO, HCONH2, CO2, H2O and cyanogen (for all the compounds) and para-toluidine (for the para-CH3 derivative), aniline (for para-OCH3, para-OC2H5 and unsubstituted derivatives) and acetaldehyde (for the para-OC2H5 derivative) were clearly observed. No alcohol emissions were recorded for either compound containing the para-OCH3- or para-OC2H5-substitututed phenyl ring. These results confirmed that the pyrolysis and oxidative decomposition of the investigated annelated triazinylacetohydrazides occurred according to the radical mechanism. Moreover, in the presence of oxygen, the reactions of volatiles and residues with oxygen (oxidation) and the combustion process additionally proceeded.


Assuntos
Dióxido de Carbono , Pirólise , Toluidinas , Estudos Prospectivos , Etanol , Compostos de Anilina , Oxigênio , Estresse Oxidativo
15.
Int J Mol Sci ; 25(8)2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38674003

RESUMO

A novel photocatalytic nanomaterial, Ho2YSbO7, was successfully synthesized for the first time using the solvothermal synthesis technique. In addition, a Ho2YSbO7/Bi2MoO6 heterojunction photocatalyst (HBHP) was prepared via the hydrothermal fabrication technique. Extensive characterizations of the synthesized samples were conducted using various instruments, such as an X-ray diffractometer, a Fourier transform infrared spectrometer, a Raman spectrometer, a UV-visible spectrophotometer, an X-ray photoelectron spectrometer, and a transmission electron microscope, as well as X-ray energy dispersive spectroscopy, photoluminescence spectroscopy, a photocurrent test, electrochemical impedance spectroscopy, ultraviolet photoelectron spectroscopy, and electron paramagnetic resonance. The photocatalytic activity of the HBHP was evaluated for the degradation of diuron (DRN) and the mineralization of total organic carbon (TOC) under visible light exposure for 152 min. Remarkable removal efficiencies were achieved, with 99.78% for DRN and 97.19% for TOC. Comparative analysis demonstrated that the HBHP exhibited markedly higher removal efficiencies for DRN compared to Ho2YSbO7, Bi2MoO6, or N-doped TiO2 photocatalyst, with removal efficiencies 1.13 times, 1.21 times, or 2.95 times higher, respectively. Similarly, the HBHP demonstrated significantly higher removal efficiencies for TOC compared to Ho2YSbO7, Bi2MoO6, or N-doped TiO2 photocatalyst, with removal efficiencies 1.17 times, 1.25 times, or 3.39 times higher, respectively. Furthermore, the HBHP demonstrated excellent stability and reusability. The mechanisms which could enhance the photocatalytic activity remarkably and the involvement of the major active species were comprehensively discussed, with superoxide radicals identified as the primary active species, followed by hydroxyl radicals and holes. The results of this study contribute to the advancement of efficient heterostructural materials and offer valuable insights into the development of sustainable remediation strategies for addressing DRN contamination.


Assuntos
Bismuto , Diurona , Luz , Molibdênio , Fotólise , Bismuto/química , Catálise , Molibdênio/química , Diurona/química , Poluentes Químicos da Água/química
16.
Int J Mol Sci ; 25(13)2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38999979

RESUMO

This study presents a pioneering synthesis of a direct Z-scheme Y2TmSbO7/GdYBiNbO7 heterojunction photocatalyst (YGHP) using an ultrasound-assisted hydrothermal synthesis technique. Additionally, novel photocatalytic nanomaterials, namely Y2TmSbO7 and GdYBiNbO7, were fabricated via the hydrothermal fabrication technique. A comprehensive range of characterization techniques, including X-ray diffractometry, Fourier-transform infrared spectroscopy, Raman spectroscopy, UV-visible spectrophotometry, X-ray photoelectron spectroscopy, transmission electron microscopy, X-ray energy-dispersive spectroscopy, fluorescence spectroscopy, photocurrent testing, electrochemical impedance spectroscopy, ultraviolet photoelectron spectroscopy, and electron paramagnetic resonance, was employed to thoroughly investigate the morphological features, composition, chemical, optical, and photoelectric properties of the fabricated samples. The photocatalytic performance of YGHP was assessed in the degradation of the pesticide acetochlor (AC) and the mineralization of total organic carbon (TOC) under visible light exposure, demonstrating eximious removal efficiencies. Specifically, AC and TOC exhibited removal rates of 99.75% and 97.90%, respectively. Comparative analysis revealed that YGHP showcased significantly higher removal efficiencies for AC compared to the Y2TmSbO7, GdYBiNbO7, or N-doped TiO2 photocatalyst, with removal rates being 1.12 times, 1.21 times, or 3.07 times higher, respectively. Similarly, YGHP demonstrated substantially higher removal efficiencies for TOC than the aforementioned photocatalysts, with removal rates 1.15 times, 1.28 times, or 3.51 times higher, respectively. These improvements could be attributed to the Z-scheme charge transfer configuration, which preserved the preferable redox capacities of Y2TmSbO7 and GdYBiNbO7. Furthermore, the stability and durability of YGHP were confirmed, affirming its potential for practical applications. Trapping experiments and electron spin resonance analyses identified active species generated by YGHP, namely •OH, •O2-, and h+, allowing for comprehensive analysis of the degradation mechanisms and pathways of AC. Overall, this investigation advances the development of efficient Z-scheme heterostructural materials and provides valuable insights into formulating sustainable remediation strategies for combatting AC contamination.


Assuntos
Luz , Toluidinas , Catálise , Toluidinas/química , Fotólise , Poluentes Químicos da Água/química , Processos Fotoquímicos , Espectroscopia Fotoeletrônica , Gadolínio/química
17.
J Environ Manage ; 359: 120979, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38692033

RESUMO

If pharmaceutical wastewater is not managed effectively, the presence of residual antibiotics will result in significant environmental contamination. In addition, inadequate utilization of agricultural waste represents a squandering of resources. The objective of this research was to assess the efficacy of iron-doped biochar (Fe-BC) derived from peanut shells in degrading high concentrations of Tetracycline (TC) wastewater through activated peroxymonosulfate. Fe-BC demonstrated significant efficacy, achieving a removal efficiency of 87.5% for TC within 60 min without the need to adjust the initial pH (20 mg/L TC, 2 mM PMS, 0.5 g/L catalyst). The degradation mechanism of TC in this system involved a dual action, namely Reactive Oxygen Species (ROS) and electron transfer. The primary active sites were the Fe species, which facilitated the generation of SO4•-, •OH, O2•-, and 1O2. The presence of Fe species and the C=C structure in the Fe-BC catalyst support the electron transfer. Degradation pathways were elucidated through the identification of intermediate products and calculation of the Fukui index. The Toxicity Estimator Software Tool (T.E.S.T.) suggested that the intermediates exhibited lower levels of toxicity. Furthermore, the system exhibited exceptional capabilities in real water and circulation experiments, offering significant economic advantages. This investigation provides an efficient strategy for resource recycling and the treatment of high-concentration antibiotic wastewater.


Assuntos
Carvão Vegetal , Ferro , Espécies Reativas de Oxigênio , Tetraciclina , Águas Residuárias , Tetraciclina/química , Carvão Vegetal/química , Espécies Reativas de Oxigênio/química , Águas Residuárias/química , Ferro/química , Poluentes Químicos da Água/química , Peróxidos/química , Transporte de Elétrons
18.
J Environ Manage ; 364: 121435, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38889646

RESUMO

The abuse and uncontrolled discharge of antibiotics present a severe threat to environment and human health, necessitating the development of efficient and sustainable treatment technology. In this work, we employ a facile one-step electrodeposition method to prepare polyaniline/graphite oxide (PANI/GO) and samarium (Sm) co-modified Ti/PbO2 (Ti/PbO2-PANI/GO-Sm) electrode for the degradation of amoxicillin (AMX). Compared with traditional Ti/PbO2 electrode, Ti/PbO2-PANI/GO-Sm electrode exhibits more excellent oxygen evolution potential (2.63 V) and longer service life (56 h). In degradation experiment, under optimized conditions (50 mg L-1 AMX, 20 mA cm-2, pH 3, 0.050 M Na2SO4, 25 °C), Ti/PbO2-PANI/GO-Sm electrode achieves remarkable removal efficiencies of 88.76% for AMX and 79.92% for chemical oxygen demand at 90 min. In addition, trapping experiment confirms that ·OH plays a major role in the degradation process. Based on theoretical calculation and liquid chromatography-mass spectrometer results, the heterocyclic portion of AMX molecule is more susceptible to ·OH attacks. Thus, this novel electrode offers a sustainable and efficient solution to address environmental challenges posed by antibiotic-contaminated wastewater.


Assuntos
Amoxicilina , Eletrodos , Amoxicilina/química , Titânio/química , Poluentes Químicos da Água/química , Samário/química
19.
J Environ Manage ; 370: 122798, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39362166

RESUMO

High valent metal species, including Mn(III), Fe(IV) and Cu(III), have been identified as key intermediates in the degradation of pollutants in many advanced oxidation processes. However, unlike Mn(III) and Fe(IV), the current exploration of the reaction activity and selective oxidation mechanism of Cu(III) towards pollutants with different structures is still quite limited. Herein, the copper(III) periodate was synthesized to investigate the reactivity towards six sulfonamide antibiotics (SAs) including typical two pentacyclic structures (sulfamethoxazole (SMX) and sulfathiazole (STZ)) and four hexacyclic structures (sulfadiazine (SDZ), sulfamerazine (SMR), sulfamonomethoxine (SMM) and sulfapyridine (SPD)). The results indicated that all SAs almost completely removed by Cu(III) system after 10 min with the molar ratio of approximately 3:1 (Cu(III):SAs) and Cu(III) direct oxidation played the most important role. SAs with 6-ring substituents were more readily degraded by Cu(III) than SAs with 5-ring substituents, and the presence of electron-rich group such as -CH3 and -S in ring substituent increased the reactivity towards Cu(III). The introduction of coexisting anions (Cl-, SO42- and HCO3-) hardly affected the degradation of SAs by Cu(III) oxidation, while the addition of HA to some extent inhibited SAs degradation. The solution pH greatly affected the degradation of SAs by Cu(III) and the removal efficiencies of SAs roughly followed the rule of neutral > acidic > alkaline. The degradation mechanism of SAs with 5-ring and 6-ring substituents in Cu(III) system mainly included amino nitration, self-coupling, hydroxylation, S-N cleavage in SAs with 5-ring substituents and SO2 extrusion in SAs with 6-ring substituents. Although the real water matrix inhibited the degradation of SAs to varying degrees, Cu(III) still played a satisfactory performance on SAs degradation especially for electron-rich structure.

20.
J Environ Manage ; 352: 120044, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38184867

RESUMO

The increasing contamination of water systems by antibiotics and heavy metals has become a growing concern. The intimately coupled photocatalysis and biodegradation (ICPB) approach offers a promising strategy for the effective removal of mixed pollutants. Despite some prior research on ICPB applications, the mechanism by which ICPB eliminates mixed pollutants remains unclear. In our current study, the ICPB approach achieved approximately 1.53 times the degradation rate of ciprofloxacin (CIP) and roughly 1.82 times the reduction rate of Cr (VI) compared to photocatalysis. Remarkably, after 30 days, the ICPB achieved a 96.1% CIP removal rate, and a 97.8% reduction in Cr (VI). Our investigation utilized three-dimensional fluorescence analysis and photo-electrochemical characterization to unveil the synergistic effects of photocatalysis and biodegradation in removal of CIP and Cr (VI). Incorporation of B-Bi3O4Cl (B-BOC) photocatalyst facilitated electron-hole separation, leading to production of ·O2-, ·OH, and h+ species which interacted with CIP, while electrons reduced Cr (VI). Subsequently, the photocatalytic products were biodegraded by a protective biofilm. Furthermore, we observed that CIP, acting as an electron donor, promoted the reduction of Cr (VI). The microbial communities revealed that the number of bacteria favoring pollutant removal increased during ICPB operation, leading to a significant enhancement in performance.


Assuntos
Ciprofloxacina , Poluentes Ambientais , Antibacterianos , Biodegradação Ambiental , Cromo/química , Catálise
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