Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Small ; 20(1): e2304776, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37658502

RESUMEN

Efficient artificial photosynthesis of disulfide bonds holds promises to facilitate reverse decoding of genetic codes and deciphering the secrets of protein multilevel folding, as well as the development of life science and advanced functional materials. However, the incumbent synthesis strategies encounter separation challenges arising from leaving groups in the ─S─S─ coupling reaction. In this study, according to the reaction mechanism of free-radical-triggered ─S─S─ coupling, light-driven heterojunction functional photocatalysts are tailored and constructed, enabling them to efficiently generate free radicals and trigger the coupling reaction. Specifically, perovskites and covalent organic frameworks (COFs) are screened out as target materials due to their superior light-harvesting and photoelectronic properties, as well as flexible and tunable band structure. The in situ assembled Z-scheme heterojunction MAPB-M-COF (MAPbBr3 = MAPB, MA+ = CH3 NH2 + ) demonstrates a perfect trade-off between quantum efficiency and redox chemical potential via band engineering management. The MAPB-M-COF achieves a 100% ─S─S─ coupling yield with a record photoquantum efficiency of 11.50% and outstanding cycling stability, rivaling all the incumbent similar reaction systems. It highlights the effectiveness and superiority of application-oriented band engineering management in designing efficient multifunctional photocatalysts. This study demonstrates a concept-to-proof research methodology for the development of various integrated heterojunction semiconductors for light-driven chemical reaction and energy conversion.

2.
Molecules ; 28(24)2023 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-38138503

RESUMEN

Visible-light-driven N2 reduction into NH3 in pure H2O provides an energy-saving alternative to the Haber-Bosch process for ammonia synthesizing. However, the thermodynamic stability of N≡N and low water solubility of N2 remain the key bottlenecks. Here, we propose a solution by developing a WO3-x hollow sphere with oxygen vacancies. Experimental analysis reveals that the hollow sphere structure greatly promotes the enrichment of N2 molecules in the inner cavity and facilitates the chemisorption of N2 onto WO3-x-HS. The outer layer's thin shell facilitates the photogenerated charge transfer and the full exposure of O vacancies as active sites. O vacancies exposed on the surface accelerate the activation of N≡N triple bonds. As such, the optimized catalyst shows a NH3 generation rate of 140.08 µmol g-1 h-1, which is 7.94 times higher than the counterpart WO3-bulk.

3.
RSC Adv ; 13(51): 36477-36483, 2023 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-38099249

RESUMEN

The construction of heterojunctions has been used to optimize photocatalyst fuel denitrification. In this work, HKUST-1(Cu) was used as a sacrificial template to synthesize a composite material CuxO (CuO/Cu2O) that retains the original MOF framework for photocatalytic fuel denitrification by calcination at different temperatures. By adjusting the temperature, the content of CuO/Cu2O can be changed to control the performance and structure of CuxO-T effectively. The results show that CuxO-300 has the best photocatalytic performance, and its denitrification rate reaches 81% after 4 hours of visible light (≥420 nm) irradiation. Through the experimental analysis of pyridine's infrared and XPS spectra, we found that calcination produces CuxO-T mixed-valence metal oxide, which can create more exposed Lewis acid sites in the HKUST-1(Cu) framework. This leads to improved pyridine adsorption capabilities. The mixed-valence metal oxide forms a type II semiconductor heterojunction, which accelerates carrier separation and promotes photocatalytic activity for pyridine denitrification.

4.
Dalton Trans ; 52(47): 17785-17791, 2023 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-37990557

RESUMEN

The rapid recombination of charge carriers in semiconductor-based photocatalysts results in a low photocatalytic activity. Co-catalysis is considered a promising strategy to improve the photocatalytic performance of semiconductors. In this study, a bimetallic phosphide was grown by a facile in situ growth method. Loading the cocatalyst (7 wt% NiCoP) leads to activity enhancement by a factor of approximately 27 times in the visible-light-driven hydrogen evolution relative to the pristine Zn0.5Cd0.5S. The photocatalysis shows a high hydrogen evolution rate of 19.5 mmol g-1 h-1, which is much higher than that of the single metal phosphide (Ni2P: 7.0 mmol g-1 h-1; CoxP: 8.1 mmol g-1 h-1) and 7 wt% Pt modified Zn0.5Cd0.5S (0.3 mmol g-1 h-1). Its apparent quantum efficiency reaches 41.6% at 420 nm. Moreover, the photocatalyst exhibits a remarkable photostability for five consecutive cycles of photocatalytic activity measurements with a total reaction time of 15 hours. The excellent photocatalytic activity of the photocatalyst was attributed to the in situ-formed NiCoP cocatalyst, which not only acts as a reactive site but also accelerates the separation of charge carriers.

5.
Dalton Trans ; 52(23): 7869-7875, 2023 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-37212428

RESUMEN

Developing novel photocatalysts with an intimate interface and sufficient contact is significant for the separation and migration of photogenerated carriers. In this work, a novel Co@NC/ZnIn2S4 heterojunction with a strong Co-S chemical bond was formed at the interface between Co@NC and ZnIn2S4, which accelerated charge separation. Meanwhile, the recombination of the electron-hole pairs was further restricted by the Co@NC/ZnIn2S4 Schottky junction. The Co@NC (5 wt%)/ZnIn2S4 composite exhibited an H2 evolution rate of 33.3 µmol h-1, which is 6.1 times higher than that of the pristine ZnIn2S4, and Co@NC/ZnIn2S4 showed excellent stability in the photocatalytic water splitting reaction. Its apparent quantum yield reached 38% at 420 nm. Furthermore, the Kelvin probe test results showed that the interfacial electric field formed as the driving force for interface charge transfer was oriented from Co@NC to ZnIn2S4. In addition, the Co-S bond as a high-speed channel facilitated the interfacial electron transfer. This work reveals that in situ formed chemical bonds will pave the way for designing high-efficiency heterojunction photocatalysts.

6.
Dalton Trans ; 52(9): 2845-2852, 2023 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-36756969

RESUMEN

Knowledge of the photocatalytic H2-evolution mechanism is of critical importance for water splitting, and for designing active catalysts for a sustainable energy supply. In this study, we prepared plasmon Au-modified K-doped defective graphitic carbon nitride (Au/KCNx) and then applied it in photocatalytic hydrogen-production tests. The hydrogen-production rate of the Au/KCNx photocatalyst (8.85 mmol g-1 h-1) was found to be almost 104 times higher than that of Au/g-C3N4 (0.085 mmol g-1 h-1), together with an apparent quantum efficiency of 12.8% at 420 nm. It could significantly improve the photocatalytic activities of the Au/KCNx sample, which was attributed to the synergistic effects of the plasmon effect, potassium doping, and nitrogen vacancy. In addition, the Au/KCNx photocatalyst had a large surface area, which was beneficial for photogenerated carrier separation and transfer. The novel strategy proposed here is a potential new method for the development of graphitic carbon nitride photocatalysts with obviously enhanced activities.

7.
Dalton Trans ; 52(2): 290-296, 2023 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-36484709

RESUMEN

The rapid recombination of photogenerated carriers and strong photocorrosion have considerably limited the practical application of CdS in the field of photocatalysis. Loading a cocatalyst has been widely utilized to largely enhance photocatalytic activity. In the present work, a WC@C cocatalyst was prepared by a novel molten salt method and explored as an efficient noble-metal-free cocatalyst to significantly enhance the photocatalytic hydrogen evolution rate of CdS nanorods. The WC@C/CdS composite photocatalyst with a 7 wt% content of WC@C showed the highest photocatalytic hydrogen evolution rate of 8.84 mmol g-1 h-1, which was about 21 and 31 times higher than those of CdS and 7 wt% Pt/CdS under visible light irradiation. A high apparent quantum efficiency (AQY) of 55.28% could be achieved under 420 nm monochromatic light. Furthermore, the photocatalytic activity of the 7 wt% WC@C/CdS photocatalyst exhibited good stability for 12 consecutive cycles of the photocatalytic experiment with a total reaction time of 42 h. The excellent photocatalytic performance of the photocatalyst was attributed to the formation of a Schottky junction and the loading cocatalyst, which not only accelerated the separation of the photogenerated carrier but also provided a reactive site for hydrogen evolution. This work revealed that WC@C could act as an excellent cocatalyst for enhancing the photocatalytic activity of CdS nanorods.

8.
Phys Chem Chem Phys ; 25(1): 117-123, 2022 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-36475462

RESUMEN

The enhancement of photogenerated carrier separation efficiency is a significant factor in the improvement of photocatalyst performance in photocatalytic hydrogen evolution. Heteroatom doping and defect construction have been considered valid methods to boost the photocatalytic activity of graphitic carbon nitride. Herein, we report graphitic carbon nitride modified with P doping and N defects (PCNx), and the effects of doping and defects were investigated in photocatalytic H2 evolution. Its hydrogen evolution rate can reach up to about 59.1 µmol h-1, which is more than 123.1 times higher than pristine graphitic carbon nitride under visible light irradiation. Importantly, the apparent quantum efficiency reaches 8.73% at 420 nm. The excellent performance of the PCNx photocatalyst was attributed to the following aspects: (I) the large BET surface area of PCNx affords more active sites for H2 production and (II) the introduction of P and N defects can accelerate the charge carrier separation and transfer efficiency, leading to more efficient photocatalytic hydrogen production. The photocatalyst showed obviously enhanced activities.

9.
Molecules ; 27(21)2022 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-36364316

RESUMEN

The construction of a multi-component heterostructure for promoting the exciton splitting and charge separation of conjugated polymer semiconductors has attracted increasing attention in view of improving their photocatalytic activity. Here, we integrated Au nanoparticles (NPs) decorated CeO2 (Au-CeO2) with polymeric carbon nitride (PCN) via a modified thermal polymerization method. The combination of the interfacial interaction between PCN and CeO2 via N-O or C-O bonds, with the interior electronic transmission channel built by the decoration of Au NPs at the interface between CeO2 and PCN, endows CeAu-CN with excellent efficiency in the transfer and separation of photo-induced carriers, leading to the enhancement of photochemical activity. The amount-optimized CeAu-CN nanocomposites are capable of producing ca. 80 µmol· H2 per hour under visible light irradiation, which is higher than that of pristine CN, Ce-CN and physical mixed CeAu and PCN systems. In addition, the photocatalytic activity of CeAu-CN remains unchanged for four runs in 4 h. The present work not only provides a sample and feasible strategy to synthesize highly efficient organic polymer composites containing metal-assisted heterojunction photocatalysts, but also opens up a new avenue for the rational design and synthesis of potentially efficient PCN-based materials for efficient hydrogen evolution.

10.
Molecules ; 27(17)2022 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-36080206

RESUMEN

Modulating the transport route of photogenerated carriers on hollow cadmium sulfide without changing its intrinsic structure remains fascinating and challenging. In this work, a series of well-defined heterogeneous hollow structural materials consisting of CdS hollow nanocubes (CdS NCs) and graphitic C3N4 nanoparticles (CN NPs) were strategically designed and fabricated according to an electrostatic interaction approach. It was found that such CN NPs/CdS NCs still retained the hollow structure after CN NP adorning and demonstrated versatile and remarkably boosted photoreduction performance. Specifically, under visible light irradiation (λ ≥ 420 nm), the hydrogenation ratio over 2CN NPs/CdS NCs (the mass ratio of CN NPs to CdS NCs is controlled to be 2%) toward nitrobenzene, p-nitroaniline, p-nitrotoluene, p-nitrophenol, and p-nitrochlorobenzene can be increased to 100%, 99.9%, 83.2%, 93.6%, and 98.2%, respectively. In addition, based on the results of photoelectrochemical performances, the 2CN NPs/CdS NCs reach a 0.46% applied bias photo-to-current efficiency, indicating that the combination with CN NPs can indeed improve the migration and motion behavior of photogenerated carriers, besides ameliorating the photocorrosion and prolonging the lifetime of CdS NCs.

11.
RSC Adv ; 12(20): 12702-12709, 2022 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-35480366

RESUMEN

Effective design of photocatalysts is an effective method to improve the separation of photogenerated carriers, which improves the photocatalytic performance of photocatalysts. In this work, CoCu-ZIF materials with bimetallic structure were synthesized at room temperature for efficient photocatalytic fuel denitrification. The properties and structures of CoCu-ZIF photocatalysts can be effectively controlled by adjusting the molar ratio of cobalt to copper. The as-prepared CoCu-ZIF photocatalysts were characterized by XRD, FT-IR, SEM, TEM, UV-vis, Raman, BET and other techniques. The photoactivity of CoCu-ZIF for the denitrogenation of NCCs has been evaluated using visible light (λ ≥ 420 nm). The results indicate that Co8Cu2-ZIF photocatalysts exhibit excellent photocatalytic properties, in which the denitrification rate almost reached 80% after 4 hours under visible light irradiation, which is higher than the degradation ability of ZIF-67 (38%). Transient photoelectrochemical experiments and EIS Nyquist plots indicate that Co8Cu2-ZIF with unique structure efficiently improves the separation and transfer of photogenerated electron-hole pairs. Moreover, a possible reaction mechanism was proposed by LC-MS analysis.

12.
Spectrochim Acta A Mol Biomol Spectrosc ; 268: 120675, 2022 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-34890871

RESUMEN

Infrared spectroscopy is a powerful tool for the understanding of molecular structure and function of polypeptides. Theoretical interpretation of IR spectra relies on ab initio calculations may be very costly in computational resources. Herein, we developed a neural network (NN) modeling protocol to evaluate a model dipeptide's backbone amide-I spectra. DFT calculations were performed for the amide-I vibrational motions and structural parameters of alanine dipeptide (ALAD) conformers in different micro-environments ranging from polar to non-polar ones. The obtained backbone dihedrals, C = O bond lengths and amide-I frequencies of ALAD were gather together for NN architecture. The applications of built NN protocols for the prediction of amide-I frequencies of ALAD in other solvation conditions are quite satisfactory with much less computational cost comparing with electronic structure calculations. The results show that this cost-effective way enables us to decipher the polypeptide's dynamic secondary structures and biological functions with their backbone vibrational probes.


Asunto(s)
Amidas , Dipéptidos , Alanina , Simulación de Dinámica Molecular , Redes Neurales de la Computación , Espectrofotometría Infrarroja , Vibración
13.
Molecules ; 28(1)2022 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-36615476

RESUMEN

New surface coordination photocatalytic systems that are inspired by natural photosynthesis have significant potential to boost fuel denitrification. Despite this, the direct synthesis of efficient surface coordination photocatalysts remains a major challenge. Herein, it is verified that a coordination photocatalyst can be constructed by coupling Pd and CTAB-modified ZnIn2S4 semiconductors. The optimized Pd/ZnIn2S4 showed a superior degradation rate of 81% for fuel denitrification within 240 min, which was 2.25 times higher than that of ZnIn2S4. From the in situ FTIR and XPS spectra of 1% Pd/ZnIn2S4 before and after pyridine adsorption, we find that pyridine can be selectively adsorbed and form Zn⋅⋅⋅C-N or In⋅⋅⋅C-N on the surface of Pd/ZnIn2S4. Meanwhile, the superior electrical conductivity of Pd can be combined with ZnIn2S4 to promote photocatalytic denitrification. This work also explains the surface/interface coordination effect of metal/nanosheets at the molecular level, playing an important role in photocatalytic fuel denitrification.


Asunto(s)
Desnitrificación , Piridinas , Adsorción , Conductividad Eléctrica , Fotosíntesis
14.
Molecules ; 26(24)2021 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-34946648

RESUMEN

Effectively reducing the concentration of nitrogen-containing compounds (NCCs) remains a significant but challenging task in environmental restoration. In this work, a novel step-scheme (S-scheme) SnO2@MCr heterojunction was successfully fabricated via a facile hydrothermal method. At this heterojunction, MIL-101(Cr) octahedrons are decorated with highly dispersed SnO2 quantum dots (QDs, approximate size 3 nm). The QDs are evenly wrapped around the MIL-101(Cr), forming an intriguing zero-dimensional/three-dimensional (0D/3D) S-scheme heterostructure. Under simulated sunlight irradiation (280 nm < λ < 980 nm), SnO2@MCr demonstrated superior photoactivity toward the denitrification of pyridine, a typical NCC. The adsorption capacity and adsorption site of SnO2@MCr were also investigated. Tests using 20%SnO2@MCr exhibited much higher activity than that of pure SnO2 and MIL-101(Cr); the reduction ratio of Cr(VI) is rapidly increased to 95% after sunlight irradiation for 4 h. The improvement in the photocatalytic activity is attributed to (i) the high dispersion of SnO2 QDs, (ii) the binding of the rich adsorption sites with pyridine molecules, and (iii) the formation of the S-scheme heterojunction between SnO2 and MIL-101(Cr). Finally, the photocatalytic mechanism of pyridine was elucidated, and the possible intermediate products and degradation pathways were discussed.

15.
Nanomaterials (Basel) ; 11(10)2021 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-34685202

RESUMEN

The design and synthesis of a Z-schematic photocatalytic heterostructure with an intimate interface is of great significance for the migration and separation of photogenerated charge carriers, but still remains a challenge. Here, we developed an efficient Z-scheme organic/inorganic g-C3N4/LDH heterojunction by in situ growing of inorganic CoAl-LDH firmly on organic g-C3N4 nanosheet (NS). Benefiting from the two-dimensional (2D) morphology and the surface exposed pyridine-like nitrogen atoms, the g-C3N4 NS offers efficient trap sits to capture transition metal ions. As such, CoAl-LDH NS can be tightly attached onto the g-C3N4 NS, forming a strong interaction between CoAl-LDH and g-C3N4 via nitrogen-metal bonds. Moreover, the 2D/2D interface provides a high-speed channel for the interfacial charge transfer. As a result, the prepared heterojunction composite exhibits a greatly improved photocatalytic H2 evolution activity, as well as considerable stability. Under visible light irradiation of 4 h, the optimal H2 evolution rate reaches 1952.9 µmol g-1, which is 8.4 times of the bare g-C3N4 NS. The in situ construction of organic/inorganic heterojunction with a chemical-bonded interface may provide guidance for the designing of high-performance heterostructure photocatalysts.

16.
Water Sci Technol ; 83(12): 2921-2930, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34185689

RESUMEN

Hg(II) ions in wastewater are highly toxic to the environment and human health, yet many materials to remove the ions exhibit lower adsorption efficiency, and few studies report the reuse of Hg(II)-loaded waste materials. Here, a cheap and efficient adsorbent was prepared for the removal of Hg(II) based on corn bracts (CB) loading copper sulfide (CuS), and the Hg(II)-adsorbed material was reused as a photocatalyst. By changing the adsorption variables such as pH, adsorbent dosage, Hg(II) concentration, contact time and coexisting ions, the optimum adsorption conditions were obtained. The study indicated the adsorption capacity and removal rate of CB/CuS reached 249.58 mg/g and 99.83% at pH 6 with 20 mg CB/CuS, 50 mL Hg(II) concentration (100 mg/L) and 60 min, and coexisting ions did not affect the uptake of Hg(II). The adsorption behavior of CB/CuS toward Hg(II) followed pseudo-second-order and Langmuir models, with the theoretical maximum adsorption capacity of 316.46 mg/g. Finally, we explored an alternative strategy to dispose of spent adsorbents by converting the CB/CuS/HgS into a photocatalyst for the degradation of rhodamine B, with a removal rate of 98%. Overall, this work not only develops a promising material for the treatment of Hg(II)-containing wastewater, but opens up a new approach for the use of the waste adsorbent.


Asunto(s)
Mercurio , Contaminantes Químicos del Agua , Adsorción , Cobre , Humanos , Concentración de Iones de Hidrógeno , Cinética , Mercurio/análisis , Sulfuros , Contaminantes Químicos del Agua/análisis , Zea mays
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 259: 119918, 2021 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-33991814

RESUMEN

Molecular dynamics simulations and DFT calculations were performed for the demonstration of the structural dynamics and vibrational feature of N-Acetyl-d-glucosamine (NAG) in solution phase. The interactions between NAG and solvent molecules were evaluated through spatial distribution function and radial distribution function, and the preferred conformations of NAG in aqueous solution were revealed by cluster analysis. Results from normal mode analysis show that the solvent induced structural fluctuation of NAG could be reflected in the vibrational feature of specific chromophores, thus we can evaluate the molecular structure with the help of its vibrational signature based on the built correlation between molecular structure and vibrational frequencies of specific groups.


Asunto(s)
Acetilglucosamina , Glucosamina , Simulación de Dinámica Molecular , Vibración , Agua
18.
Int J Biol Macromol ; 182: 1120-1129, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33892041

RESUMEN

In this study, a new tannic acid cross-linking cellulose/polyethyleneimine functionalized magnetic composite (MCP) as a biomass adsorbent of Hg(II) ions was prepared. The morphology and structure of MCP were characterized with FT-IR, TG, XRD, SEM and TEM. The effect of the different factors such as pH, contact time, initial Hg(II) ion concentration, and adsorption temperature on the adsorption behavior was investigated. The results showed that MCP exhibited an excellent selectivity and reutilization, fast removal rate, and very high adsorption capacity. The corresponding adsorption capacity and removal rate of could reach 99.00% and 247.51 mg/g when the pH value, adsorption time, Hg(II) ion concentration were 5, 180 min and 100 mg/L at 293 K. The kinetics followed the pseudo-second-order, which indicated that the adsorption behavior of MCP for Hg(II) ion belonged to the chemical adsorption process and external diffusion. The thermodynamic study showed that the adsorption process was a spontaneous and exothermic process. After the fifth adsorption-desorption experiment, it still had better adsorption performance and reutilization. All in all, MCP with highly stable and efficient, as well as excellent reusability will be a candidate for industry-level applications from wastewater with Hg(II) ions.


Asunto(s)
Celulosa/análogos & derivados , Polietileneimina/análogos & derivados , Taninos/química , Adsorción , Celulosa/química , Concentración de Iones de Hidrógeno , Polietileneimina/química , Termodinámica
19.
Dalton Trans ; 50(7): 2596-2605, 2021 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-33522547

RESUMEN

In this work, a novel step-scheme (S-scheme) Bi2MoO6/CdS heterojunction (HJ) photocatalyst (PC) was successfully prepared by a two-step solvothermal method for the first time. One-dimensional CdS nanorods were prepared by a simple solvothermal method as a synthesis template. Then, a Bi2MoO6 precursor was added to obtain a series of Bi2MoO6/CdS HJ composite catalytic materials with different morphologies. The photocatalytic performance of the catalyst was investigated by simulating fuel denitration as a probe reaction under visible light excitation (>420 nm). When compared with pure Bi2MoO6 and CdS, the 0.65-Bi2MoO6/CdS composite shows the highest photocatalytic activity for pyridine degradation. Degradation of pyridine reached 81% after 240 min of visible light excitation. The degradation rate of 0.65-Bi2MoO6/CdS reached 0.4471 h-1, which was 1.8 and 3.2 times higher than that of CdS (0.2493 h-1) and Bi2MoO6 (0.1427 h-1), respectively. Combined with a series of characterisation results, the improvement in pyridine degradation activity was mainly attributed to (1) the S-scheme HJ structure between Bi2MoO6 and CdS, which greatly promoted the separation of photogenerated electrons and holes while retaining its strong redox ability, (2) the large specific surface area, which provided abundant active sites and efficient adsorption performance and catalytic performance, and (3) the special morphology, which induced multiple reflections of light, thereby improving absorption and utilisation of light. Moreover, after four cycles of pyridine denitrification, the samples still exhibited high activity, indicating good stability and recyclability of the composite catalyst. These findings provide a basis for the development of composite PCs for efficient fuel denitration under visible light irradiation.

20.
Ecotoxicology ; 30(7): 1389-1398, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33420882

RESUMEN

Carboxylated multi-walled carbon nanotubes (MWCNT-COOH) exerts strong adsorption capacity for pentachlorophenol (PCP) and they inevitably co-occur in the environment, but few studies have characterized the effects of MWCNT-COOH on the bioavailability of PCP and its oxidative and tissue damages to fish. In this work, we assessed the PCP accumulation in different organs and the induced oxidative and tissue damages of goldfish following 50-d in vivo exposure to PCP alone or co-exposure with MWCNT-COOH. Our results indicated that PCP bioaccumulation in goldfish liver, gill, muscle, intestine and gut contents was inhibited after co-exposure with MWCNT-COOH in uptake phase. PCP exposure alone and co-exposure with MWCNT-COOH evoked severe oxidative and tissue damages in goldfish bodies, as indicated by significant inhibition of activities of antioxidant enzymes, remarkable decrease in glutathione level, simultaneous elevation of malondialdehyde content, and obvious histological damages to liver and gill. The decreased accumulation of PCP in the presence of MWCNT-COOH led to the reduction of PCP-induced toxicity to liver tissues, as confirmed by the alleviation of hepatic oxidative damages. However, co-exposure groups had higher concentrations of PCP in the tissues than PCP treatment alone (p < 0.05 each) in the depuration phase, revealing that MWCNT-COOH-bound pollutants might pose higher risk once desorbed from the nanoparticles. These results provided substantial information regarding the combined effects of PCP and MWCNT-COOH on aquatic species, which helps to deeply understand the potential ecological risks of the emerging pollutants.


Asunto(s)
Nanotubos de Carbono , Pentaclorofenol , Animales , Bioacumulación , Carpa Dorada , Nanotubos de Carbono/toxicidad , Estrés Oxidativo , Pentaclorofenol/toxicidad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...