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1.
J Environ Manage ; 304: 114319, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-35021592

RESUMO

Prunus Armeniaca seed (PAS) oil was utilised as a waste biomass feedstock for biodiesel production via a novel catalytic system (SrO-La2O3) based on different stoichiometric ratios. The catalysts have been characterised and followed by a parametric analysis to optimise catalyst results. The catalyst with a stoichiometric ratio of Sr: La-8 (Sr-La-C) using parametric analysis showed an optimum yield of methyl esters is 97.28% at 65 °C, reaction time 75 min, catalyst loading 3 wt% and methanol to oil molar ratio of 9. The optimum catalyst was tested using various oil feedstocks such as waste cooking oil, sunflower oil, PAS oil, date seed oil and animal fat. The life cycle assessment was performed to evaluate the environmental impacts of biodiesel production utilising waste PAS, considering 1000 kg of biodiesel produced as 1 functional unit. The recorded results showed the cumulative abiotic depletion of fossil resources over the entire biodiesel production process as 22,920 MJ, global warming potential as 1150 kg CO2 equivalent, acidification potential as 4.89 kg SO2 equivalent and eutrophication potential as 0.2 kg PO43- equivalent for 1 tonne (1000 kg) of biodiesel produced. Furthermore, the energy ratio (measured as output energy divided by input energy) for the entire production process was 1.97. These results demonstrated that biodiesel obtained from the valorisation of waste PAS provides a suitable alternative to fossil fuels.


Assuntos
Biocombustíveis , Prunus armeniaca , Animais , Catálise , Estágios do Ciclo de Vida , Óleos Vegetais
2.
J Environ Manage ; 302(Pt B): 114046, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34775338

RESUMO

This paper reviews the new progress, challenges and barriers on production of pyrolysis oil from the plastic waste. Among the different processes thermal and catalytic are the potential methods to produce oil. Since the global plastic production increased over years the accumulation of plastic waste increases. Thus, converting the waste plastics into useful energy is very essential to avoid the environmental concerns. Initially the thermal pyrolysis process and its advantage on production of pyrolysis oil were discussed. During the thermal decomposition the waste plastic had been converted into the products such as gas, crude oil and solid residues. Secondly, the catalytic process and its recent trends were discussed. In addition, the factors affecting the catalytic pyrolysis process had been evaluated. Furthermore, the optimized concentration of catalyst subjected to the higher yield of fuel with low hydrocarbon content was found. The pyrolysis oil produced from the catalytic process has higher heating values, lower density and lower viscosity compared to thermal process. In addition, the application of pyrolysis oil on the diesel engines had been discussed. The effects of pyrolysis oil on combustion and emission characteristics were observed. This review summarizes the potential advantages and barriers of both thermal and catalytic process. Further, the optimized solutions and applications of pyrolysis oil are suggested for sustainability of the process. Besides the introduction of the pyrolysis oil were viable without making major modification to the existing engine design.


Assuntos
Plásticos , Pirólise , Catálise , Hidrocarbonetos
3.
J Colloid Interface Sci ; 608(Pt 1): 1040-1050, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34785452

RESUMO

The development of photocatalytic systems composed of earth-abundant metal-based catalysts for efficient production of clean fuel, H2 as well as value-added chemicals is of significant importance towards sustainable generation of energy resources. Consequently, herein we report rational construction of Z-scheme CoTiO3/xZn0.5Cd0.5S (x = 5 (S1), 10 (S2), 15 (S3) and 20 wt% (S4)) heterostructures featuring suitable band structure for efficient photocatalytic reduction of protons of water to H2 combined with selective oxidation of furfuryl alcohol (biomass derivative) to a value-added product, furfuraldehyde. Electron microscopy analysis of heterostructure S2 revealed that Zn0.5Cd0.5S nanoparticles are decorated over the surface of CoTiO3 microrods. The photocatalytic studies showed higher catalytic performance by S2, for selective oxidation of furfuryl alcohol to furfuraldehyde with 95% yield coupled with a H2 generation rate of 1929 µmol g-1h-1 which is about 4-fold higher than that of pristine Zn0.5Cd0.5S. The enhanced catalytic performance of heterostructure S2 has been ascribed to synergistic interaction aided by the Z-scheme heterojunction formation between CoTiO3 and Zn0.5Cd0.5S. Overall, this work demonstrates the application of noble metal-free photocatalyst for simultaneous production of H2 and value-added chemical under mild and environment-friendly conditions.


Assuntos
Cádmio , Hidrogênio , Catálise , Luz , Zinco
4.
J Colloid Interface Sci ; 608(Pt 1): 1051-1063, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34785453

RESUMO

Organic semiconductors have been recognized as a new generation of photocatalysts for pollutants degradation and energy production. Herein, organic heterojunction (TpMa/CN) consisting of carbon nitride and ß-ketoenamine-based covalent organic framework is fabricated via a controllable self-assembly approach. The as-prepared TpMa/CN heterojunctions show enlarged visible-light absorption. The optimum TpMa/CN-5 photocatalyst achieves the highest photocatalytic activity towards tetracycline degradation, and its photocatalytic degradation rate is improved by 2.3 and 4.3 times than TpMa and CN, respectively. As a multifunctional photocatalyst, TpMa/CN-5 sample also shows remarkable photocatalytic activity for hydrogen peroxide production (880.494 µM h-1), which is 49 times higher than that of CN. Experimental and theoretical investigations indicate that a built-in electric field is formed at the interface of composite, which enables an accelerated charge transfer and separation. This work develops an effective strategy to design difunctional photocatalyst and deciphers the electronic properties and mechanisms of g-C3N4-based organic photocatalysts, which spurs further interests for organic heterojunction photocatalysts in the future.


Assuntos
Estruturas Metalorgânicas , Tetraciclina , Catálise , Luz , Semicondutores
5.
J Colloid Interface Sci ; 608(Pt 1): 800-808, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34785457

RESUMO

Electro-oxidation of glycerol is a key anodic reaction in direct alcohol fuel cell (DAFCs). Exploring the cost-effective nanocatalysts for glycerol oxidation reaction (GOR) is very important for the development of DAFC, but it is still challenging. In this paper, nanofirework-like PtRu alloy catalyst was successfully synthesized and used for GOR in alkaline medium. Thanks to the unique nanofirework-like structure and synergetic effects, the activity and stability of the as-prepared PtRu alloy nanofireworks (NFs) toward GOR were significantly improved relative to Pt NFs. In particular, the peak current density of GOR catalyzed by the optimized Pt1Ru3 NFs catalyst reached 2412.0 mA mg-1, surpassing that of commercial Pt/C catalyst. This work has important guidance for the design of advanced anode electrocatalysts for fuel cells.


Assuntos
Ligas , Glicerol , Catálise , Oxirredução , Platina
6.
J Colloid Interface Sci ; 608(Pt 1): 954-962, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34785470

RESUMO

A novel N-rich sugarcane-like photocatalyst CdS/C3N5 (CCN) was prepared by a thermal polymerization method and tested for generating H2 and realizing antiphotocorrosive performance. The best photocatalytic H2 evolution is obtained for a CdS to C3N5 mass ratio of 1:1 (CCN3), which is nearly 33 and 3 times higher than that of pure C3N5 and CdS, respectively. CCN3 can be used to effectively reduce CdS photocorrosion and increase stability because of its N-rich performance and sugarcane-like structure, which can affect electron transport and enhance the internal binding force, respectively. CCN3 can maintain a high H2 evolution ability after 5 cycles, while still maintaining the original sugarcane-like shape, which has an anti-photocorrosive ability.


Assuntos
Hidrogênio , Nitrogênio , Biomimética , Compostos de Cádmio , Catálise , Luz , Sulfetos
7.
J Hazard Mater ; 423(Pt A): 127061, 2022 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-34788939

RESUMO

While sulphur dioxide (SO2) is known for its toxicity, numerous effective countermeasures were innovated to alleviate its hazards towards the environment. In particular, catalytic reduction is favoured for its potential in converting SO2 into harmless, yet marketable product, such as elemental sulphur. Therefore, current review summarises the critical findings in catalytic SO2 reduction, emphasising on both dry- and wet-based technology. As for the dry-based technology, knowledge related to SO2 reduction over metal-, rare earth- and carbon-based catalysts are summarised. Significantly, both the reduction mechanisms and important criteria for efficient SO2 reduction are elucidated too. Meanwhile, the wet-based SO2 reduction are typically conducted in reactive liquid medium, such as metal complexes, ionic liquids and organic solvents. Therefore, the applications of the aforesaid liquid mediums are discussed thoroughly in the similar manner to dry-technology. Additionally, the pros and cons of each type of catalyst are also presented to provide valuable insights to the pertinent researchers. Finally, some overlooked aspects in both dry- and wet-based SO2 reduction are identified, with potential solutions given too. With these insights, current review is anticipated to contribute towards practicality improvement of catalytic SO2 reduction, which in turn, protects the environment from SO2 pollution.


Assuntos
Dióxido de Enxofre , Enxofre , Carbono , Catálise , Tecnologia
8.
J Environ Manage ; 302(Pt B): 114119, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34794052

RESUMO

Metal-doped MgFe2O4 spinel ferrite synthesized from saprolite laterite nickel ore was verified as an efficient heterogeneous Fenton-like catalyst for degrading antibiotics including tetracycline (TC) and metronidazole (MNZ) in a "catalyst/oxalic acid (H2C2O4)/visible light (vis)" system. The degradation efficiencies reached over 95% and total organic carbon (TOC) removal efficiencies were nearly 50% of the two antibiotics within 210 min, under the optimal conditions, especially 90% catalytic activity of the fresh catalyst was maintained after five cycles, suggesting the ferrite possessed excellent degrading performance, cycling stability and applicability. Moreover, the degradation mechanism and pathway of TC were elucidated in detail. Results revealed that the [≡Fe(C2O4)3]3- complex ions formed by octahedral Fe3+ in spinel ferrite with oxalate ions on the surface of MgFe2O4, played the key role in production of ·OH radicals which decomposed antibiotic TC into small molecules even mineralized in three pathways. Cost-effective preparation, high catalytic performance and long cycle life may accelerate the practical application of the heterogeneous Fenton-like catalyst.


Assuntos
Antibacterianos , Águas Residuárias , Catálise , Peróxido de Hidrogênio , Fenômenos Magnéticos
9.
Chemosphere ; 286(Pt 1): 131558, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34293564

RESUMO

Visible light induced photocatalysis converted solar energy to chemical energy in the form of hydrogen. g-C3N4 modified by thermal oxidation etching, doped S, and nonprecious metal cocatalyst CoS2 (CoS2@SCN) were used for photocatalytic hydrogen production. And then the charge transfer behavior and mechanism of various alcohol sacrificial agents on hydrogen evolution was analyzed by optical characterization, impedance analysis, Mott-Schottky, and photocurrent tests. The relationship between the structure and catalytic performance was also explored using characterization methods. The results showed that CoS2 significantly improved the light absorption of g-C3N4, and carrier migration and separation. And when the sacrificial agent was triethanolamine, the nanocomposite CoS2@SCN exhibited best catalytic performance with the highest hydrogen activity of 223.6 µmol g-1 h-1, the minimum volume in-phase charge transfer resistance with 55.19 Ω and the maximum photocurrent and photocurrent density with 5.5 µA cm-2 and 0.63 mA cm-2. The more negatively charged surface of organic alcohols were, the easier they were to react with holes, thus enhanced charge transfer and hydrogen production efficiency. This report provides guidance for the selection of hydrogen producing sacrificial agents and preparation of highly charge-efficient catalysts. And it also provides a theoretical basis for hydrogen production from wastewater and environmental remediation.


Assuntos
Hidrogênio , Nanoestruturas , Álcoois , Catálise , Luz
10.
Chemosphere ; 286(Pt 1): 131541, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34293565

RESUMO

To effectively degrade organic pollutants in wastewater, visible-light-driven Bi2MoO6/PPy hierarchical heterogeneous photocatalysts were prepared through a solvothermal method and the following in-situ chemical oxidation polymerization. Compared with pristine Bi2MoO6 photocatalyst, the composite photocatalysts exhibited dramatically improved photocatalytic activity and photostability towards the degradation of methylene blue dye and tetracycline antibiotic. Bi2MoO6/PPy-80 sample achieved the highest photocatalytic degradation rates for methylene blue dye (93.6%) and tetracycline antibiotic (88.3%) under visible light irradiation. These two organic pollutants could be completely degraded into nontoxic small molecules according to in-depth HPLC-MS analysis of degradation products. The transient photocurrent responses, electrochemical impedance spectra, and photoluminescence spectra demonstrated that the introduction of PPy nanoparticles on the surface of Bi2MoO6 nanosheets could effectively accelerate the separation of photo-generated electron-hole pairs. Furthermore, a possible synergetic photocatalytic mechanism was put forward based on the electron spin resonance and XPS valence-band spectra. This work indicated that construction of hierarchical composite photocatalysts combining polypyrrole conductive polymer and Bi2MoO6 semiconductor in nanoscale is an efficient approach to improve photocatalytic activity for environmental remediation.


Assuntos
Poluentes Ambientais , Polímeros , Bismuto , Catálise , Descontaminação , Microesferas , Molibdênio , Pirróis
11.
Chemosphere ; 286(Pt 1): 131608, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34298296

RESUMO

In this study, cuprous oxide modified titanate nanotube arrays photocatalyst (Cu2O/TNAs), a p-n type hetero-structure, was successfully synthesized by square wave voltammetry electrodeposition method (SWVE) with copper (II) acetate monohydrate as precursor. Cu2O/TNAs photocatalysts were characterized by SEM, XRD, XPS, and UV-vis DRS to investigate the physical and chemical properties such as surface structure, light absorption, and element composition. Results of characterization indicated that the Cu2O nanoparticles (Cu2O NPs) were firmly deposited on the surface of TNAs without significant morphological change. The enhanced photocatalytic (PC) performance of as-synthesized materials was exemplified by the test of photocurrent, which revealing that the average photocurrent density of Cu2O/TNAs (0.95 µA cm-2) was 1.38 times higher than TNAs (0.69 µA cm-2) under 24.2 mW cm-2 LED irradiation. Three VOCs (volatile organic compounds), namely, Toluene, Formaldehyde and Trichloroethylene can be completely removed in the Cu2O/TNAs PC process with rate constants (kobs) of 2.08 × 10-2, 3.11 × 10-2, and 6.58 × 10-2 min-1, respectively, with the effort of the synergism of the photo-generated holes and hydroxyl radicals. Detail mechanism of hetero-junction Cu2O/TNAs composite PC system was proposed to clarify the redox reaction.


Assuntos
Nanotubos , Tricloroetileno , Catálise , Cobre , Formaldeído , Tolueno
12.
Food Chem ; 366: 130523, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34303206

RESUMO

Our study offers a novel sn-1,3 specific lipase MAJ1 from marine member Janibacter sp. strain HTCC2649 for preparing long-medium-long (LML) type structured triacylglycerols (TAGs). Firstly, the resin ECR1030 was selected as a suitable support for the immobilization of lipase MAJ1. An efficient synthesis of LML-type structured TAGs by the immobilized lipase MAJ1-catalyzed interesterification of methyl palmitate and tricaprylin was studied in a solvent-free system. The reaction conditions, including substrate molar ratio, temperature and enzyme loading, were optimized. Under the optimum conditions (immobilized lipase MAJ1 of 45 U/g, substrate molar ratio of 4:1, temperature of 35 °C, reaction time of 24 h), the structured TAGs with double long chains (DLCST) were obtained in a yield of 44.3 mol%. Secondly, multi-dimensional mass spectrometry-based shotgun lipidomics (MDMS-SL) was employed to quantify each TAG positional isomer in DLCST. The content of 1,3-dipalmitoyl-2-capryloyl-sn-glycerol in DLCST was 97.6% determined by the MDMS-SL technology.


Assuntos
Enzimas Imobilizadas , Lipase , Catálise , Esterificação , Lipase/metabolismo , Solventes , Temperatura , Triglicerídeos
13.
J Colloid Interface Sci ; 605: 1-12, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34303921

RESUMO

A series of BiO(OH)xI1-x solid solution (SS) catalysts were successfully prepared by ion exchange of I- and OH- between the [Bi2O2]2+ layers. The morphology and microstructure were studied in depth using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Brunauer-Emmett-Teller (BET) method, etc. Tunable absorption in the visible-light region was achieved by changing the proportion of OH- to I-. Due to the etching effect of OH-, oxygen vacancies (OVs) greatly increased for the SS catalysts, and were confirmed by X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), and electron paramagnetic spectroscopy (EPR). The unique composition of OH-, I-, OV, and [Bi2O2]2+ layers in BiO(OH)xI1-x materials resulted in diverse photoexcitations. The BiO(OH)0.45I0.55 photocatalyst displayed a 10-fold-improved 2-chlorophenol (2-CP) degradation rate compared to BiOI. The interfacial reaction process by the photoinduced valence-band holes and conduction-band electrons proved to be a more efficient pathway for organic pollutant degradation by the BiO(OH)xI1-x SS photocatalyst. The OVs in the SS photocatalyst facilitated photoexcited and electron migration and transformation.


Assuntos
Luz , Oxigênio , Catálise , Espectroscopia Fotoeletrônica , Difração de Raios X
14.
J Hazard Mater ; 421: 126674, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34315025

RESUMO

Photocatalytic degradation of organic dyes has been considered one of the promising solutions that enabled to effectively treat the demanding pollutants in wastewater. Yet, insight into the photocatalytic process under both illumination and dark conditions were hitherto missing. Herein, by virtue of incorporating the core-shell Au@CuxS nanoparticles to the ZnO nanowalls synthesized via all-solution synthesis, the intriguing heterostructures allowed to trigger the extraordinary capability of dye degradation either under light irradiance or dark environment. It was found that the coexistence of bi-constituted Cu2S/CuS shells on Au nanoparticles obtained with turning the concentrations of sulfurization acted as the decisive role on day-night active degradation performance, where the degradation efficiency was more than 8.3 times beyond sole ZnO sheets. The mediation of remarkable visible-light absorption and efficient charge separation due to band alignment of heterojunctions were responsible for the improved photodegradation efficiency under visible illuminations. Moreover, at dark environment, the involving peroxidase-like activity of CuxS shells with the mediation of Au nanoparticles facilitated the catalytic formation of hydroxyl radicals, manifesting the oxidative degradation of MB dye. Such all-day active photocatalysts further displayed the capability for the recycling treatment of MB dye, which offered the pathways to potentially treat the organic wastewater.


Assuntos
Nanopartículas Metálicas , Óxido de Zinco , Catálise , Ouro , Fotólise
15.
J Hazard Mater ; 421: 126703, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34315026

RESUMO

Water eutrophication leads to increasingly serious harmful algal blooms (HABs), which poses tremendous threats on aquatic environment and human health. In this work, a novel magnetically separable ZnFe2O4/Ag3PO4/g-C3N4 (ZFO/AP/CN) photocatalyst with double Z-scheme was constructed for Microcystis aeruginosa (M. aeruginosa) inactivation and Microcystin-LR (MC-LR) degradation under visible light. The photocatalyst was characterized by XRD, SEM, EDS, TEM, XPS, FTIR, UV-vis, PL, and VSM. Approximately 96.33% of chlorophyll a was degraded by ZFO/AP/CN (100 mg/L) after 3 h of visible light irradiation. During the photocatalytic process, the malondialdehyde (MDA) of M. aeruginosa increased, the activities of superoxide dismutase (SOD) and catalase (CAT) increased initially and decreased afterwards. Furthermore, the photocatalytic removal efficiency of M. aeruginosa (OD680 ≈0.732) and MC-LR (0.2 mg/L) reached 94.31% and 76.92%, respectively, in the simultaneous removal of algae and algal toxin experiment. Reactive species scavenging experiments demonstrated that·O2- and·OH played key roles in inactivating M. aeruginosa and degrading MC-LR. The excellent recoverability and stability of ZFO/AP/CN were proved by cycling photocatalytic experiment which using magnetic recovery method. In summary, the synthesized magnetically separable ZFO/AP/CN photocatalyst has remarkable photocatalytic activity under visible light and shows promising potential for practical application of alleviating HABs.


Assuntos
Microcystis , Catálise , Clorofila A , Proliferação Nociva de Algas , Luz
16.
Chemosphere ; 286(Pt 1): 131640, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34315085

RESUMO

The morphology and specific surface area of layered double hydroxide (LDH) are of great significance for optimizing the application of LDH in sewage treatment. Herein, we present a study of the relation between the catalytic property and the morphology of LDH via activating peroxymonosulfate (PMS) for degradation of organic pollutants. The results demonstrated that LDH nanoscrolls possessed a superior performance for methylene blue (MB) degradation, which achieved almost 100% removal in 40 min and the calculated apparent rate constant was about 2.1, 4.5 and 11.5 times higher than that of LDH nanosheets, Co2+ and Co3O4, respectively. According to the results of X-ray photoelectrons spectroscopy (XPS) and electron paramagnetic resonance (EPR), 1O2 was confirmed to play a dominant role in the MB degradation, where the redox cycle of Co3+/Co2+ provided the impetus for the reaction. Moreover, the pH and ion tolerance abilities of LDH nanoscrolls in PMS activating process were determined as well. Remarkably, CO32- and H2PO4- could even promote the generation of •OH and 1O2 to facilitate the progress of reaction. Overall, these findings in the study may provide more opportunities in the preparation of high-efficiency catalysts and give insight into the accelerated degradation of refractory contaminants with surrounding anions.


Assuntos
Hidróxidos , Peróxidos , Catálise , Oxirredução
17.
Chemosphere ; 286(Pt 1): 131612, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34325262

RESUMO

We use first principle approaches to study the adsorption and catalytic activation mechanism of CO2 on ionic liquids (ILs, [CnMIm]+[Cl]- (n = 0-6)) attached to a Au(111) surface. The adsorption of CO2 at this liquid-solid model interface occurs via either (i) parallel π-stacking mode or (ii) CO2 oxygen lone pair (lp)···π interaction. These CO2 physisorption modes, which depend on the CO2 landing angle at this interface, are identified as an efficient way to activate CO2 and its further conversion into value-added products. For illustration, we discuss the conversion of CO2 into formic acid where the ILs@Au(111) decorated interface allows reduction of the activation energy for the CO2 + H2 → HCOOH reaction. In sum, our electrode/electrolyte based interface model provides valuable information to design novel heterogeneous catalysts for CO2 conversion. Indeed, our work establishes that a suitable interface material is enough to activate CO2.


Assuntos
Líquidos Iônicos , Adsorção , Dióxido de Carbono , Catálise , Oxigênio
18.
Food Chem ; 366: 130650, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34330030

RESUMO

Mixed lauric acid esters (MLE) with antibacterial and antioxidative activities were produced through lipase-catalyzed two-step esterification in solvent-free system without purification. In the first reaction, erythorbyl laurate was synthesized for 72 h. Successive reaction for 6 h at molar ratio of 1.0 (lauric acid to glycerol) produced MLE containing erythorbyl laurate and glyceryl laurate with small amounts of residual substrates, by converting 99.52% of lauric acid. MLE addition (0.5-2.0%, w/w) to Tween 20-stabilized emulsions decreased droplet size, polydispersity index, and zeta-potential, possibly enhancing the emulsion stability. In the emulsions, MLE at 0.5 and 2.0% (w/w) caused 4.4-4.6 and 5.9-6.1 log reductions of Gram-positive (Staphylococcus aureus, Listeria monocytogenes) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), respectively, within 12 h. Lipid hydroperoxide concentrations decreased to 50.8-98.3% in the presence of 0.5-2.0% (w/w) MLE. These findings support a novel approach without needing purification to produce multi-functional food additives for emulsion foods.


Assuntos
Ésteres , Lipase , Antibacterianos/farmacologia , Antioxidantes , Catálise , Esterificação , Ácidos Láuricos , Lipase/metabolismo , Solventes
19.
J Hazard Mater ; 421: 126634, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34330077

RESUMO

Developing sheet-on-sheet (2D/2D) heterostructure with built-in electric field (BIEF) is effective in boosting the performance of photocatalysts for emerging contaminants degradation. Herein, the 2D/2D microtopography and (-)TiO2/(+)Bi2MoO6 BIEF were precisely integrated into hierarchical nanosheets, which can provide the basis and driving force for charge transfer both in in-plane and interface of heterojunction. The prepared photocatalyst (TiO2/Bi2MoO6) showed high-efficiency and stable performance for photocatalytic amoxicillin (AMX) degradation, which was 18.2 and 5.7 times higher than TiO2 and Bi2MoO6, respectively. More importantly, TiO2/Bi2MoO6 showed more efficient photocatalytic activity and photogenerated charge separation than TiO2@Bi2MoO6 (different morphology). Besides, four possible pathways of AMX degradation were proposed depending on Gaussian calculations and intermediates analysis by GC-MS and HPLC-TOFMS. This work sheds light on the design and construction of unique 2D/2D heterostructure photocatalysts for AMX degradation.


Assuntos
Amoxicilina , Bismuto , Catálise , Molibdênio , Titânio
20.
J Colloid Interface Sci ; 605: 214-222, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34332404

RESUMO

Although a number of nanozymes have been developed, it is still difficult to develop single-component nanozyme with overall high multienzyme-like activities. In this study, the nanosized metal-organic frameworks (nano-MOFs) FePCN (PCN stands for porous coordination network) was synthesized by integrating zirconium and iron ions with different catalytic property on single-component MOFs and exhibited superior intrinsic multienzyme-like activities, namely oxidase-, peroxidase- and phosphatase-mimicking activity. The catalytic active sites of oxidase- and peroxidase-, and phosphatase-like activity of FePCN were Fe-centers and Zr-O clusters, respectively. Based on the intrinsic oxidase-like activity and the similarity of molecular structures between cytochrome P450 oxidase (CYP) cofactors and the organic linker in FePCN, FePCN exhibited high CYP-like activity to catalyze the oxidation of hypotensive drug 1,4-dihydropyridine (1,4-DHP) into diethyl 2,6-dimethylpyridine-3,5-dicarboxylate (DDPD) and the yield of DDPD reached over 80%. Moreover, as peroxidase- and phosphatase-mimics, FePCN was successfully applied to detecting H2O2 under neutral condition and catalyzing the dephosphorylation of adenosine triphosphate (ATP), respectively. This study provides a feasible way for rational design one-component nanomaterials as multienzyme-mimics.


Assuntos
Di-Hidropiridinas , Estruturas Metalorgânicas , Catálise , Peróxido de Hidrogênio
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