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1.
Water Environ Res ; 96(4): e11027, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38659148

RESUMEN

In this study, we synthesized magnetic MnFe2O4/ZIF-67 composite catalysts using a straightforward method, yielding catalysts that exhibited outstanding performance in catalyzing the ozonation of vanillin. This exceptional catalytic efficiency arose from the synergistic interplay between MnFe2O4 and ZIF-67. Comprehensive characterization via x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), Fourier transform infrared spectrometer (FT-IR), Brunauer-Emmett-Teller (BET), field emission scanning electron microscopy (FE-SEM), and energy dispersive spectroscopy (EDS) confirmed that the incorporation of MnFe2O4 promoted the creation of oxygen vacancies, resulting in an increased presence of l adsorbed oxygen (Oads) and the generation of additional ·OH groups on the catalyst surface. Utilizing ZIF-67 as the carrier markedly enhanced the specific surface area of the catalyst, augmenting the exposure of active sites, thus improving the degradation efficiency and reducing the energy consumption. The effects of different experimental parameters (catalyst type, initial vanillin concentration, ozone dosage, initial pH value, and catalyst dosage) were also investigated, and the optimal experimental parameters (300 mg/L1.0-MnFe2O4/ZIF-67, vanillin concentration = 250 mg/L, O3 concentration = 12 mg/min, pH = 7) were obtained. The vanillin removal efficiency of MnFe2O4/ZIF-67 was increased from 74.95% to 99.54% after 30 min of reaction, and the magnetic separation of MnFe2O4/ZIF-67 was easy to be recycled and stable, and the vanillin removal efficiency of MnFe2O4/ZIF-67 was only decreased by about 8.92% after 5 cycles. Additionally, we delved into the synergistic effects and catalytic mechanism of the catalysts through kinetic fitting, reactive oxygen quenching experiments, and electron transfer analysis. This multifaceted approach provides a comprehensive understanding of the enhanced ozonation process catalyzed by MnFe2O4/ZIF-67 composite catalysts, shedding light on their potential applications in advanced oxidation processes. PRACTITIONER POINTS: A stable and recyclable magnetic composite MnFe2O4/ZIF-67 catalyst was synthesized through a simple method. The synergistic effect and catalytic mechanism of the MnFe2O4/ZIF-67 catalyst were comprehensively analyzed and discussed. A kinetic model for the catalytic ozone oxidation of vanillin was introduced, providing valuable insights into the reaction dynamics.


Asunto(s)
Benzaldehídos , Compuestos Férricos , Imidazoles , Ozono , Ozono/química , Benzaldehídos/química , Catálisis , Compuestos Férricos/química , Compuestos de Manganeso/química , Zeolitas/química , Contaminantes Químicos del Agua/química
2.
Nat Commun ; 15(1): 2241, 2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38472214

RESUMEN

Electronic structure modulation of active sites is critical important in Fenton catalysis as it offers a promising strategy for boosting H2O2 activation. However, efficient generation of hydroxyl radicals (•OH) is often limited to the unoptimized coordination environment of active sites. Herein, we report the rational design and synthesis of iron oxyfluoride (FeOF), whose iron sites strongly coordinate with the most electronegative fluorine atoms in a characteristic moiety of F-(Fe(III)O3)-F, for effective H2O2 activation with potent •OH generation. Results demonstrate that the fluorine coordination plays a pivotal role in lowering the local electron density and optimizing the electronic structures of iron sites, thus facilitating the rate-limiting H2O2 adsorption and subsequent peroxyl bond cleavage reactions. Consequently, FeOF exhibits a significant and pH-adaptive •OH yield (~450 µM) with high selectivity, which is 1 ~ 3 orders of magnitude higher than the state-of-the-art iron-based catalysts, leading to excellent degradation activities against various organic pollutants at neutral condition. This work provides fundamental insights into the function of fluorine coordination in boosting Fenton catalysis at atomic level, which may inspire the design of efficient active sites for sustainable environmental remediation.

3.
Environ Technol ; : 1-13, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38037354

RESUMEN

In this study, the porous graphite phase carbon nitride photocatalyst (P-g-C3N4) is prepared by the CaCO3 template method, and then P-g-C3N4/T-polyethylene terephthalate (T-PET) catalytic fibre is prepared by the padding method. P-g-C3N4 can provide more active sites than g-C3N4 as proved by the Brunauer-Emmett-Teller and the UV-Visible diffuse reflectance test. P-g-C3N4 powder catalyst successfully supports PET fibre as proved by scanning electron microscope, Fourier infrared spectroscopy and X-ray diffraction spectroscopy. The photocatalytic performance of P-g-C3N4/T-PET catalytic fibre is tested by constructing a single hexavalent chromium or hexavalent chromium/organic pollutant binary pollution system. The potential application value of P-g-C3N4/T-PET catalytic fibre is further explored by simulating the complex actual water environment. After five recycles, P-g-C3N4/T-PET catalytic fibre shows good catalytic performance. The mechanism of P-g-C3N4/PET photocatalytic degradation of organic pollutants is proposed through the capture agent experiment and electron paramagnetic resonance spectroscopy. Among them, •O2- is the most important active species of P-g-C3N4 catalytic fibre, which is used for the oxidation of organic pollutants. At the same time, photoelectrons generated by the catalytic fibre are used to reduce hexavalent chromium. The efficiency of P-g-C3N4 to remove pollutants is improved by using PET fibre as a carrier, which not only solves the problem of difficult recovery of powder catalysts but also provides more active sites.

4.
J Environ Sci (China) ; 139: 473-482, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38105070

RESUMEN

Microplastic pollution has become one of the most concerned focuses in the world. Among many treatment methods, photocatalysis is considered to be one of the most environmentally friendly methods. In this work, the photodegradation behavior of polyamide microplastics is studied by using polyamide 6 PA6) as model microplastics and FeCl3 as catalyst. It is hoped that the PA6 fiber can be effectively degraded by utilizing the strong oxidizing active species that can be produced after FeCl3 is irradiated in water. The results shows that PA6 fiber can be almost completely degraded after 10 days of irradiation in FeCl3 aqueous solution, indicating that it is promising to use this new method to solve the problem of PA6 type microplastics. In addition, the chain scission mechanism and degradation process of PA6 are analyzed in detail by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS), which provides a new insight for the study of polymer degradation mechanism.


Asunto(s)
Nylons , Plásticos , Microplásticos , Cromatografía Liquida , Espectrometría de Masas en Tándem/métodos , Metales
5.
Environ Technol ; : 1-13, 2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37559566

RESUMEN

In this study, each cobalt tetra-aminophthalocyanine (CoTAPc) molecule was immobilised with four isonicotinic acid (INA) molecules by amide bonding, a novel and highly efficient catalyst pyridine-bridged cobalt tetra-aminophthalocyanine (CoTAPc-TINA) was synthesised. The introduction of INA molecules promoted CoTAPc to expose more active sites, and increased the electron cloud density of cobalt ions promoting O-O bond homolysis of PMS to generate more active species, which significantly enhanced catalytic activity. With the pharmaceutical of carbamazepine (CBZ) as model pollutant, 0.1 g/L CoTAPc-TINA in dark in the presence of 0.4 mM PMS, 98.8% CBZ was removed within 10 min. However, under the same conditions the removed of CBZ was only 58.9% by CoTAPc/PMS system. Radical capture experiments combined electron paramagnetic resonance technology demonstrate that hydroxyl radicals, sulphate radicals, superoxide radicals and singlet oxygen are the main active species in the CoTAPc-TINA/PMS system. As the reaction proceeded, all aromatic intermediates were transformed to small molecular acids by these active species. This investigation provided a new insight for application of metal phthalocyanine in wastewater treatment.

6.
Adv Mater ; 35(46): e2307186, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37619540

RESUMEN

The delicate design of innovative and sophisticated fibers with vertical porous skeleton and eminent electrochemical activity to generate directional ionic pathways and good faradic charge accessibility is pivotal but challenging for realizing high-performance fiber-shaped supercapacitors (FSCs). Here, hierarchically ordered hybrid fiber combined vertical-aligned and conductive Ti3 C2 Tx MXene (VA-Ti3 C2 Tx ) with interstratified electroactive covalent organic frameworks LZU1 (COF-LZU1) by one-step microfluidic synthesis is developed. Due to the incorporation of vertical channels, abundant redox active sites and large accessible surface area throughout the electrode, the VA-Ti3 C2 Tx @COF-LZU1 fibers express exceptional gravimetric capacitance of 787 F g-1 in a three-electrode system. Additionally, the solid-state asymmetric FSCs deliver a prominent energy density of 27 Wh kg-1 , capacitance of 398 F g-1 and cycling life of 20 000 cycles. The key to high energy storage ability originates from the decreased ions adsorption energy and ameliorative charge density distribution in vertically aligned and active hybrid fiber, accelerating ions transportation/accommodation and interfacial electrons transfer. Benefiting from excellent electrochemical performance, the FSCs offer sufficient energy supply to power watches, flags, and digital display tubes as well as be integrated with sensors to detect pulse signals, which opens a promising route for architecting advanced fiber toward the carbon neutrality market beyond energy-storage technology.

7.
Langmuir ; 39(28): 9857-9864, 2023 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-37427414

RESUMEN

Titanium dioxide (TiO2) nanoparticles have been extensively used to modify the optical properties of various types of materials. In particular, they have been intensively loaded onto polymer fibers to quench the light reflection. In situ polymerization and online addition are two common strategies for fabricating TiO2-loaded polymer nanocomposite fibers. The former does not require separate preparation of masterbatches as the latter does and therefore has its advantages in terms of decreasing the fabrication steps and economic costs. Moreover, it has been found that in situ-polymerized TiO2-loaded polymer nanocomposite fibers (e.g., TiO2/poly(ethylene terephthalate) fibers) usually have enhanced light-extinction properties over those prepared by the online addition process. Intuitively, there should be a difference in the filler particle dispersion for the two fabrication processes. This hypothesis has not yet been tackled due to the technical difficulty in acquiring the three-dimensional (3D) filler morphology inside the fiber matrix. In this paper, we report a study using the powerful focused ion beam-scanning electron microscopy (FIB-SEM) with a resolution of 20 nm to directly acquire the 3D microstructure of TiO2/poly(ethylene terephthalate) nanocomposite (TiO2/PET) fibers. This microscopy technique allows us to characterize the particle size statistics and the dispersion inside TiO2/PET fibers. We have found that the particle size of TiO2 inside the fiber matrix can be well modeled by Weibull statistics. Surprisingly, we find that TiO2 nanoparticles form more significant agglomeration in the in situ-polymerized TiO2/PET fibers. This observation is contrary to our common understanding of the two fabrication processes. Namely, slightly altering the particle dispersion with increased TiO2 filler size helps improve the light-extinction properties. The slightly increased filler size may have altered the Mie scattering between the nanoparticles and the incident visible light, leading to enhanced light-extinction properties of in situ-polymerized TiO2/PET nanocomposite fibers.

8.
Angew Chem Int Ed Engl ; 62(33): e202307195, 2023 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-37340702

RESUMEN

Designing deformable supercapacitors (D-SCs) that have robust skeleton and smoothly active channels for charges kinetic migration and faradic storage are highly crucial for wearable systems. Here, we develop the high-performance D-SCs made of the covalent organic frameworks(COF)@amino-modified Ti3 C2 Tx deposited on decorated nylon 6 (DPA) film (COF@N-Ti3 C2 Tx /DPA) via layer-by-layer fabrication. The hierarchical COF@N-Ti3 C2 Tx /DPA exhibits admirable specific capacitance, rate performance and cycling stability in three-electrode system due to the superior H+ storage property and large interfacial charge transfer clarified by density functional theory calculations. Additionally, the solid-state D-SCs deliver favourable energy density and practical energy-supply applications. Particularly, the solid-state D-SCs present high deformable stabilities, with regard to 80.7, 80.6 and 83.4 % capacitance retention after 5000 bending cycles, 2000 stretching cycles and 5000 folding cycles, separately.

9.
ACS Appl Mater Interfaces ; 15(22): 26910-26917, 2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-37246367

RESUMEN

Graphdiyne (GDY) has realized significant achievements in lithium-ion batteries (LIBs) because of its unique π-conjugated skeleton with sp- and sp2-hybridized carbon atoms. Enriching the accessible surface areas and diffusion pathways of Li ions can realize more storage sites and rapid transport dynamics. Herein, three-dimensional porous hydrogen-substituted GDY (HsGDY) is developed for high-performance Li-ion storage. HsGDY, fabricated via a versatile interface-assisted synthesis strategy, exhibits a large specific surface area (667.9 m2 g-1), a hierarchical porous structure, and an expanded interlayer space, which accelerate Li-ion accessibility and lithiation/delithiation. Owing to this high π-conjugated, conductive, and porous framework, HsGDY exhibits a large reversible capacity (930 mA h g-1 after 100 cycles at 1 A g-1), superior cycle (720 mA h g-1 after 300 cycles at 1 A g-1), and rate (490 mA h g-1 at 5 A g-1) performances. Density functional theory calculations of the low diffusion barrier in the lamination and vertical directions further reveal the fast Li-ion transport kinetics of HsGDY. Additionally, a LiCoO2-HsGDY full cell is constructed, which exhibits a good practical charge/discharge capacity of 128 mA h g-1 and stable cycling behavior. This study highlights the advanced design of next-generation LIBs to sustainably develop the new energy industry.

10.
Angew Chem Int Ed Engl ; 62(20): e202301618, 2023 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-36916126

RESUMEN

Fiber-shaped supercapacitors (FSCs) have become one of the significantly strategical flexible energy-storage materials towards future wearable textile electronics and metaverse technologies. Here, we develop the high-performance FSCs based on multiscale dot-wire-sheet heterostructure microfiber of nitrogen-doped carbon dots-Ti3 C2 Tx /silk nanofibers (NCDs-Ti3 C2 Tx /SNFs) hybrids via microfluidic fabrication. Due to the enlarged interlayer spacing, plentiful porous channels, accelerated H+ ion transport dynamics, large electrical conductivity and excellent mechanical strength/flexibility, the NCDs-Ti3 C2 Tx /SNFs possesses high volumetric capacitance (2218.7 F cm-3 ) and reversible charge-discharge stability in 1 M H2 SO4 electrolyte. Furthermore, the solid-state FSCs present high energy density (57.9 mWh cm-3 ), good capacitance (1157 F cm-3 ), long-life cycles (82.3 % capacitance retention after 40000 cycles), which realize the actual energy-supply applications (powering lamp, watch and toy car).

11.
J Environ Sci (China) ; 126: 517-530, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36503778

RESUMEN

Graphite carbon nitride has many excellent properties as a two-dimensional semiconductor material so that it has a wide application prospect in the field of photocatalysis. However, the traditional problems such as high recombination rate of photogenerated carriers limit its application. In this work, we introduce nitrogen deficiency into g-C3N4 to solve this problem a simple and safe in-situ reduction method. g-C3N4/CaCO3 was obtained by a simple and safe one-step calcination method with industrial-grade micron particles CaCO3. Cyano group modification was in-situ reduced during the thermal polymerization process, which would change the internal electronic structure of g-C3N4. The successful combination of g-C3N4 and CaCO3 and the introduction of cyanide have been proved by Fourier transform infrared spectroscopy and X-ray photoelectron spectrometer. The formation of the cyano group, an electron-absorbing group, promotes the effective separation of photogenic electron hole pairs and inhibits the recombination of photogenic carriers. These advantages result in the generation of more •O2- and 1O2 in the catalytic system, which increases the photocatalytic efficiency of nicotine degradation by ten times. Furthermore, the degradation process of nicotine has been studied in this work to provide a basis for the degradation of nicotine organic pollutants in the air.


Asunto(s)
Contaminantes Ambientales , Nicotina , Catálisis , Cianuros , Electrones
12.
Environ Technol ; 44(23): 3491-3503, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35437123

RESUMEN

Iron (II) phthalocyanine (FePc) is loaded on the surface of the tourmaline (TM) by the reflow method to obtain FePc/TM. This research effectively prevents the π-π stacking of FePc, increased the effective utilization rate of PMS activation under solar light, and further improved the catalytic performance of the catalytic system. The catalytic oxidation efficiency of FePc/TM on carbamazepine (CBZ) and sulfadiazine (SD) can reach 99% under solar light for 15 and 5 min, the total organic carbon (TOC) removal rate can reach 58% and 69% under solar light for 120 min. After 6 cycles, the CBZ removal rate remained above 95%. In addition, the FePc/TM catalytic system has an excellent removal rate for other pharmaceuticals. The results of spin-trapped electron paramagnetic resonance and classical quenching experiments show that FePc/TM can effectively activate PMS to generate active species under solar light, including superoxide radical (•O2-), singlet oxygen (1O2), hydroxyl radicals(•OH), and sulphate radicals (SO4•-). The intermediates of CBZ were identified by Ultra-high performance liquid chromatography and high resolution mass spectrometry, and the degradation pathway was proposed. As the reaction progresses, all CBZ and intermediates are reduced and converted into small acids, or mineralized to H2O, CO2. This work provides an alternative method for the design of efficient activation of PMS activation catalysts under solar light to eliminate residual pharmaceuticals in actual water bodies.


Asunto(s)
Hierro , Peróxidos , Hierro/química , Peróxidos/química , Preparaciones Farmacéuticas
13.
Angew Chem Int Ed Engl ; 61(27): e202203765, 2022 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-35426464

RESUMEN

Realizing high energy-density and actual applications of fibre-based electrochemical supercapacitors (FESCs) are pivotal but challenging, as the ability to construct advanced fibres for accelerating charges kinetic diffusion and Faradaic storage remain key bottlenecks. Here, we demonstrate high-performance FESCs based on hetero-structured polymetallic oxides/porous graphene core-sheath fibres, where the large pseudo-active polymetallic oxide (PMO) sheath is uniformly loaded on a hierarchical porous graphene fibre (PGF) core. Due to the abundant micro-/mesoporous pathways, large accessible surface, excellent redox activity and good interface electron conduction, the PMO-PGF possesses high areal capacitance (2959.78 mF cm-2 ) and manageable Faradaic reversibility in a 6 M KOH electrolyte. Furthermore, the PMO-PGF-based solid-state FESCs present high energy-density (187.22 µ Wh cm-2 ), long-life cycles (95.8 % capacitive retention after 20 000 cycles), diverse-powered capabilities and actual energy-supply applications.

14.
J Hazard Mater ; 431: 128575, 2022 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-35278971

RESUMEN

Iron-based metal-organic frameworks (Fe-MOFs) have been considered competitive catalyst candidates for the effective degradation of organic pollutants via advanced oxidation processes (AOPs) due to their unique porous architecture and tunable active site structure. However, little is known about the role of synergetic relationship between porous architecture and active site exposure of Fe-MOFs on catalysis for AOPs yet. Here, we demonstrated an overlooked compromise over these two features on modulating the catalytic ozonation reactivity of MIL-53(Fe) through a timescale-dependent crystal evolution. Enabled by intramolecular hydrogen bonds, the MIL-53(Fe) was subjected to six evolution steps in terms of crystal morphology, leading to a volcano plot of catalytic ozonation reactivity for Rhodamine B (RhB) degradation versus the crystallization time. Evidence suggested that the surface area of MIL-53(Fe) decreased dramatically, while the density of accessible active site increased when prolonging crystallization time, allowing for the facile modulation of catalytic ozonation reactivity of MIL-53(Fe). Electron paramagnetic resonance and fluorescence quantification tests verified that the screened MIL-53(Fe)s had a much better capacity for ∙OH generation than benchmark ozonation catalyst α-MnO2 and α-FeOOH. Moreover, the MIL-53(Fe) with the highest reactivity (i.e., MIL-53(Fe)-18H) could effectively destruct a broad spectrum of emerging and refractory organic pollutants and allow the thorough purification of secondary effluents discharged from textile dyeing & finishing industry for in situ reuse. Therefore, our study advances the understanding of the compromise effect between porous architecture and active site on catalysis reactivity of Fe-MOFs and promotes the rational design of more effective Fe-MOFs as well as their derivatives for environmental applications.

15.
Chemosphere ; 299: 134464, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35358552

RESUMEN

It is of great significance for improving electron transmission performance by changing of the outer ring structure of iron phthalocyanine. Herein, 4 (pyridine-2, 3-yl) iron phthalocyanine (FepyPc), as N-rich pyridyl-iron phthalocyanine derivative, was introduced to degrade pharmaceutical contaminants. The catalytic degradation of organic pollutants with FepyPc was studied by activating peroxymonosulfate (PMS) at room temperature. The results clarified that the removal rate of carbamazepine (CBZ) was close to 100% within 60 min and the calculated apparent rate constant was about 2 times larger than FePc, which proved that FepyPc had superior performance. Four active species were identified for the degradation of CBZ, including superoxide radical (•O2-), singlet oxygen (1O2), sulfate radical (SO4•-) and hydroxyl radical (•OH). In addition, the possible reaction mechanism was inferred in FepyPc/PMS/sunlight system for CBZ removal. Finally, the CBZ degradation pathway was proposed by using ultra-performance liquid chromatography and high definition mass spectrometry (UPLC/HDMS). This research provided a meaningful and efficient method for the elimination of pharmaceutical contaminants.


Asunto(s)
Residuos de Medicamentos , Indoles , Peróxidos , Luz Solar , Carbamazepina , Residuos de Medicamentos/química , Compuestos Ferrosos , Indoles/química , Peróxidos/química
16.
Chemosphere ; 299: 134375, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35314181

RESUMEN

As some of the most promising alternatives to traditional non-degradable materials, photodegradable materials have advantages of environmental benignity and rapid degradation under simple conditions. In this work, nontoxic TiO2 and cost-effective g-C3N4 have been compounded in a weight of 9:1 to form a photocatalytic additive with high activity. A 25 wt% loading of this photocatalytic additive has been incorporated into the polyacrylonitrile (PAN) by centrifugal electrospinning to prepare an abiotic degradable PAN material. Our results showed that the PAN chain could be almost fully degraded within 90 h in an aqueous medium under simulated sunlight in the absence of microorganisms. Product analysis implied that degradation of the PAN chain mainly involved the breaking of -CN and C-C bonds by radicals, followed by oxidation of terminal groups to carboxyl and gradual mineralization to CO2 and H2O. This design strategy may provide new insight for the production and degradation mechanism of photodegradable polymer.


Asunto(s)
Iluminación , Luz Solar , Resinas Acrílicas , Catálisis , Titanio
17.
Environ Technol ; 43(17): 2569-2580, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33576725

RESUMEN

The current environmental problems urgently require researchers to seek an environmentally friendly, effective and easy to operate sewage treatment method. Graphite carbon nitride (g-C3N4), which has the advantages of simple preparation, safety, non-toxicity and chemical resistance, was expected to become a photocatalyst for solving environmental pollution. However, the performances of g-C3N4 still have some limitations that the electron hole recombination is fast and the powder is not easy to recover. In this study, zinc-doped graphite carbon nitride photocatalyst (Zn-g-C3N4) was mixed with polyacrylonitrile (PAN) to produce photocatalyst fibres by electrospinning. It not only solves the problem that the powder catalyst is difficult to recycle, but also effectively inhibits the recombination of photoelectron-hole pairs. Zn-g-C3N4/PAN has good photocatalytic activity for the simultaneous reduction of hexavalent chromium and degradation of pharmaceuticals. When organic pollutants are present, the reduction efficiency of hexavalent chromium was improved without affecting its own removal efficiency. The potential application value of Zn-g-C3N4/PAN catalytic fibre was further explored by simulating the complex actual water environment. The composite fibre can be easily reused and keep its superior photocatalytic performance. The mechanism of pharmaceuticals degradation was proposed, in which ∙O2- is the most important active species, which leads to the oxidation of pharmaceuticals. Besides, the photoelectrons generated by the catalyst can reduce the toxic hexavalent chromium. The efficiency of Zn-g-C3N4 to remove pollutants is improved by PAN fibre as a carrier, which not only solves the problem of difficult recovery of powder catalysts, but also provides more active sites.


Asunto(s)
Contaminantes Ambientales , Grafito , Catálisis , Cromo , Grafito/química , Compuestos de Nitrógeno , Compuestos Orgánicos , Polvos , Zinc
18.
ACS Appl Mater Interfaces ; 13(31): 37142-37151, 2021 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-34333965

RESUMEN

The local coordination structure of metal atoms in single-atom catalysts (SACs) greatly influences their catalytic performance. And for most SACs, single metal atoms were anchored on carbon materials with N or C coordination. However, the rational design of oxygen-containing SACs and analyzing its structure-performance relationship remain challenging. Herein, we used amino-rich compounds to tailor the metatungstate and fix the W atoms and finally obtained the oxygen-containing W-SACs. The structural evolution of tungsten and its coordination atoms were tracked by electrospray ionization high-definition mass spectrometry. Furthermore, aberration-corrected transmission electron microscopy, X-ray absorption fine-structure spectroscopy, and first-principles calculation results revealed that different from the traditional SACs, the WO2N2 moiety (W coordinated with two O atoms and two N atoms) may be the favored structure for W species. This special structure promoted the energy transfer for enhancing singlet oxygen generation. This work presents an efficient way to prepare more high-efficiency SACs by atomic-scale tailoring and structural evolution tracking at the molecular level.

19.
Chem Asian J ; 16(15): 2027-2030, 2021 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-34107162

RESUMEN

A palladium supported on graphitic carbon nitride (Pd/g-C3 N4 ) catalyzed carbonylative reaction of aryl bromides and arylboronic acids by has been developed for the construction of diaryl ketones. Using benzene-1,3,5-triyl triformate (TFBen) as the CO source, the reaction proceeded well to give various diaryl ketones in moderate to good yields.

20.
Angew Chem Int Ed Engl ; 60(31): 17178-17184, 2021 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-34058046

RESUMEN

Thiocarbonylation of alkynes offers an ideal procedure for the synthesis of unsaturated thioesters. A robust ligand-controlled regioselective thiocarbonylation of alkynes is developed. Utilizing boronic acid and 5-chlorosalicylic acid as the acid additive to in situ form 5-chloroborosalicylic acid (5-Cl-BSA), and bis(2-diphenylphosphinophenyl)ether (DPEphos) as the ligand, linear α,ß-unsaturated thioesters were produced in a straightforward manner. Switching the ligand to tri(2-furyl)phosphine can turn the reaction selectivity to give branched products. Remarkably, this approach also represents the first example on thiocarbonylation of internal alkynes.

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