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2.
Chemosphere ; 341: 139984, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37657696

RESUMEN

The discharge of amoxicillin (AMX) from pharmaceutical intermediates has adverse effects on aquatic ecosystems. The elimination of AMX requires advanced oxidation processes (AOPs) that utilize high-performance photocatalysts. Furthermore, the design of highly visible light photocatalysts for AOPs demands both cost-effectiveness and efficiency. In this work, a plasmon-assisted visible light photocatalyst of 2D Ag-CoFe2O4 nanohybrids was successfully synthesized and characterized with several analytical tools to degrade AMX in aqueous solutions through advanced AOPs. The results showed that the Ag-CoFe2O4 nanohybrids had excellent photocatalytic activity and stability, which could efficiently reduce the AMX concentration by 99% within 70 min under visible light irradiation. In particular, CoFe2O4 and Ag have an interfacial contact that prevents electron-hole pair recombination more effectively than pure CoFe2O4, which results in electrons in its conduction band (CB) migrating to metallic Ag sites. Thus, charge transfers between the two materials are more efficient, leading to higher photocatalytic oxidation of AMX. Furthermore, the surface plasmon of Ag nanoparticles are excited by their plasmonic resonance, which increases the absorption of visible light. The plasmon-assisted visible light photocatalyst could replace expensive and energy-intensive advanced oxidation processes (AOPs). AOPs pathways associated with AMX have been discussed in detail. The HPLC chromatogram clearly showed AMX was oxidized by four-membered B-lactam ring opening and hydroxylation with •OH. 2D Ag-CoFe2O4 heterostructure was found to be efficient, selective, and cost-effective for the degradation of several pharmaceutical compounds. Additionally, it was found to be eco-friendly and sustainable, making it a viable alternative to AOPs.


Asunto(s)
Nanopartículas del Metal , Nanopartículas del Metal/química , Ecosistema , Catálisis , Plata/química , Luz , Preparaciones Farmacéuticas
3.
Environ Res ; 222: 115280, 2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-36657593

RESUMEN

In recent years, photoelectrocatalysis of gold nanoparticles (Au NPs) has received considerable attention due to their potential to improve catalytic efficiency. Herein, ultra-small Au NPs were successfully synthesized in a single pot using olea europea leaf extract as a green reducing agent for the degradation of 4-nitrophenol. The TEM images showed uniform distribution and spherical shape of Au NPs with an average diameter of 5 nm. Taking advantage of the ability of Au nanoparticles to absorb visible and near-infrared light, 4-nitrophenol can be successfully reduced in the presence of NaBH4. Additionally, the electrochemical activity of the fabricated Au photocathode was investigated by linear sweep voltammetry in the dark and at VIS-NIR light irradiation. This showed an increased photocurrent density of 27 mA cm-2 with an onset potential of -0.71 V. This indicates that the Au photocathode is highly active at VIS-NIR light. Interestingly, the Au photocathode showed a higher current density of 37 mA cm-2 with an onset potential of -0.6 V in the presence of 4-nitrophenol during VIS-NIR irradiation, indicating that 4-nitrophenol was efficiently reduced by the photocathode. The Au photocathode completely reduced 4-nitrophenol in the wastewater within 35 min. Recyclability studies showed that the Au NPs photocathode exhibited higher stability over multiple cycles, confirming the ability of the electrode to treat wastewater over a longer period of time. This study demonstrates the effectiveness of the photoelectrochemical (PEC) process in reducing organic compounds in wastewater.


Asunto(s)
Nanopartículas del Metal , Olea , Nanopartículas del Metal/química , Oro/química , Aguas Residuales
4.
Environ Pollut ; 316(Pt 2): 120612, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36368550

RESUMEN

Alarming rates of water contamination by toxic herbicides have prompted the need and attention for easy, efficient, and affordable treatment options with a touch of circular economy aspects. This study valorized date palm leaf (DPL) wastes into a valuable adsorbent for remediating agricultural wastewater polluted with 2,4-Dichlorophenoxyacetic acid (2,4-DPA) herbicide. The DPL precursor was modified with H2SO4 treatment and both biomass samples were characterized by various analytical techniques. Acid treatment modified the morphology, thermal, and textural properties of the final product (TDPL) while maintaining the structure and surface chemistry intact. Simulated wastewaters containing 2,4-DPA were subsequently treated using TDPL as an adsorbent. Optimum adsorption conditions of pH 2, dosage 0.95 g/L, shaking speed 200 rpm, time 120 min, and temperature 30 °C showed a good herbicide removal efficiency in the range of 55.1-72.6% for different initial feed concentrations (50-250 mg/L). Experimental kinetic data were better represented by the pseudo-second-order model, while the Freundlich isotherm was reliable in describing the equilibrium behavior of the adsorption system. Further, the thermodynamic analysis revealed that the adsorption occurred spontaneously, favorably, and exothermically. Plausible sorption mechanism involved electrostatic interactions, weak van der Waals forces, hydrogen bonds, and π-π interactions between the participating phases. Conspicuously, TDPL application to real-world situations of treating actual herbicide-polluted agricultural runoff resulted in a 69.4% remediation efficiency. Thus, the study demonstrated the valorization of date palm leaves into a valuable and industry-ready adsorbent that can sequester toxic 2,4-DPA herbicide contaminant from aqueous streams.


Asunto(s)
Herbicidas , Phoeniceae , Contaminantes Químicos del Agua , Adsorción , Herbicidas/análisis , Contaminantes Químicos del Agua/análisis , Concentración de Iones de Hidrógeno , Cinética , Termodinámica , Fenoxiacetatos , Ácido 2,4-Diclorofenoxiacético/química , Hojas de la Planta/química
5.
Curr Res Food Sci ; 5: 823-834, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35592693

RESUMEN

In the food quality and safety arena, there is a need to develop novel and sustainable methodologies that can help in the prevention of foodborne diseases. Herein, we report the development of a rapid conducting polymer strip-based sensor using Polyaniline-pectin (PANI-PEC) for the detection of Escherichia coli in milk and milk products. Polyaniline-pectin nanoparticles stabilized with biopolymer pectin were synthesized and its characterization studies such as FTIR, UV-Vis spectroscopy, electrical conductivity and particle size analysis were done. The assay parameters were optimized for the selective detection of E. coli in milk and milk products. The concentration of PANI-PEC solution immobilized/strip was optimized to be 3 mg/mL as it exhibited good sensitivity and colour intensity. Based on acid production and selectivity for E.coli, concentrations of media components like lactose, tryptophan, yeast extract, chondroitin sulphate, sodium lauryl sulphate, potassium chloride, tergitol-7, gentamycin sulphate and ampicillin trihydrate were optimized as 0.9, 0.1, 0.45, 0.015, 0.1, 2, 0.0125, 0.00016 and 0.015 respectively and sample volume was optimized to 500 µL. The developed PANI-PEC colorimetric strip-based sensor detects 0.52 ± 0.17 log CFU/mL E. coli within 10: 21 h (h). Further shelf-life study revealed that the developed PANI-PEC colorimetric sensor strips are stable at room temperature up to six months exhibiting the same sensitivity. The results obtained here indicate that this novel and simple paper based colorimetric sensor holds potential for application in food industries as a reliable and rapid method for detection of E. coli in milk and milk products at various stages of production and processing.

6.
Chemosphere ; 299: 134752, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35513083

RESUMEN

The present work reports the study on the green synthesis of hydroxyapatite (HAP) nanoadsorbents using Peltophorum pterocarpum pod extract. HAP nanoadsorbents were characterized by using FESEM, EDS, TEM, XRD, FTIR, XPS, and BET analyses. The results highlighted the high purity, needle-like aggregations, and crystalline nature of the prepared HAP nanoadsorbents. The surface area was determined as 40.04 m2/g possessing mesopores that can be related to the high adsorption efficiency of the HAP for the removal of a toxic dye, - Acid Blue 113 (AB 113) from water. Central Composite Design (CCD) was used for optimizing the adsorption process, which yielded 94.59% removal efficiency at the optimum conditions (dose: 0.5 g/L, AB 113 dye concentration: 25 ppm, agitation speed: 173 rpm, and adsorption time: 120 min). The adsorption kinetics followed the pseudo-second-order model (R2:0.9996) and the equilibrium data fitted well with the Freundlich isotherm (R2:0.9924). The thermodynamic parameters indicated that the adsorption of AB 113 was a spontaneous and exothermic process. The highest adsorption capacity was determined as 153.85 mg/g, which suggested the promising role of green HAP nanoadsorbents in environmental remediation applications.


Asunto(s)
Durapatita , Contaminantes Químicos del Agua , Adsorción , Compuestos Azo , Concentración de Iones de Hidrógeno , Cinética , Extractos Vegetales , Contaminantes Químicos del Agua/análisis
7.
Chemosphere ; 299: 134439, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35351477

RESUMEN

Dual-functional photo (electro)catalysis (PEC) is a key strategy for removing coexisting heavy metals and phenolic compounds from wastewater treatment systems. To design a PEC cell, it is crucial to use chemically stable and cost-effective bifunctional photocatalysts. The present study shows that ruthenium metallic nanoparticles decorated with CoFe2O4/RGO (Ru-CoFe2O4/RGO) are effective bifunctional photoelectrodes for the reduction of Cr(VI) ions. Ru-CoFe2O4/RGO achieves a maximum Cr(VI) reduction rate of 99% at 30 min under visible light irradiation, which is much higher than previously reported catalysts. Moreover, PEC Cr(VI) reduction rate is also tuned by adding varying concentration of phenol. A mechanism for the concurrent removal of Cr(VI) and phenol has been revealed over a bifunctional Ru-CoFe2O4/RGO catalyst. A number of key conclusions emerged from this study, demonstrating the dual role of phenol during Cr(VI) reduction by PEC. Anodic oxidation of phenol produces the enormous H+ ion, which appears to be a key component of Cr(VI) reduction. Additionally, phenolic molecules serve as hole (h+) scavengers that reduce e-/h+ recombination, thus enhancing the reduction rate of Cr(VI). Therefore, the Ru-CoFe2O4/RGO photoelectrode exhibits a promising capability of reducing both heavy metals and phenolic compounds simultaneously in wastewater.


Asunto(s)
Nanopartículas del Metal , Fenoles , Catálisis , Cromo/química , Grafito , Oxidación-Reducción , Fenol
8.
Chemosphere ; 286(Pt 2): 131799, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34364235

RESUMEN

Hydroxyapatite-decorated activated carbon (HAp/AC) nanocomposite was synthesized and utilized as a nanofiller to fabricate a novel type of polyethersulfone (PES) nanocomposite ultrafiltration (UF) membranes. Activated carbon (AC) derived from orange peel was synthesized by low-temperature pyrolysis at 400 °C. A hydroxyapatite/AC (HAp/AC) nanocomposite was developed by a simple one-pot hydrothermal synthesis method. The UF membrane was fabricated by intercalating HAp/AC fillers into PES casting solution by the non-solvent induced phase separation (NIPS) process. The prepared membranes exhibited a lower water contact angle than the pristine PES membrane. The hybrid membrane with 4 wt% HAp/AC nanocomposite displayed 4.6 times higher pure water flux (~660 L/m2 h) than that of the pristine membrane (143 L/m2 h). In static adsorption experiments, it was found that the amount of humic acid (HA) and bovine serum albumin (BSA) adsorbed by the HAp/AC-PES hybrid membrane was much lower than that of the original membrane due to the electrostatic repulsive forces between them and the surface of the membrane. Irreversible fouling was reduced from 33 to 6 % for HA and from 46 to 8 % for BSA after HAp/AC was incorporated into the PES matrix. After 7 cycles of water-BSA-water, the HAp/AC-PES hybrid membrane maintained a high pure water flux of 540 L/m2 h with an excellent flux recovery ratio (FRR), demonstrating the long-term stability of the membranes. The developed UF membranes outperformed the original PES membranes in terms of permeability, selectivity, and antifouling.


Asunto(s)
Nanocompuestos , Ultrafiltración , Carbón Orgánico , Durapatita , Membranas Artificiales , Permeabilidad , Agua
9.
Bioengineered ; 12(2): 11239-11268, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34738876

RESUMEN

Throughout history, mushrooms have occupied an inseparable part of the diet in many countries. Mushrooms are considered a rich source of phytonutrients such as polysaccharides, dietary fibers, and other micronutrients, in addition to various essential amino acids, which are building blocks of vital proteins. In general, mushrooms offer a wide range of health benefits with a large spectrum of pharmacological properties, including antidiabetic, antioxidative, antiviral, antibacterial, osteoprotective, nephroprotective, hepatoprotective, etc. Both wild edible and medicinal mushrooms possess strong therapeutic and biological activities, which are evident from their in vivo and in vitro assays. The multifunctional activities of the mushroom extracts and the targeted potential of each of the compounds in the extracts have a broad range of applications, especially in the healing and repair of various organs and cells in humans. Owing to the presence of the aforementioned properties and rich phytocomposition, mushrooms are being used in the production of nutraceuticals and pharmaceuticals. This review aims to provide a clear insight on the commercially cultivated, wild edible, and medicinal mushrooms with comprehensive information on their phytochemical constituents and properties as part of food and medicine for futuristic exploitation. Future outlook and prospective challenges associated with the cultivation and processing of these medicinal mushrooms as functional foods are also discussed.


Asunto(s)
Agaricales/química , Agaricales/crecimiento & desarrollo , Envejecimiento/fisiología , Antiinflamatorios/farmacología , Suplementos Dietéticos , Factores Inmunológicos/farmacología , Estado Nutricional
10.
Int J Biol Macromol ; 193(Pt B): 1430-1448, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34742841

RESUMEN

Wound healing is a multi-stage process that is dynamic, interactive, and complicated. However, many nanomaterials are employed to expedite wound healing by demonstrating antibacterial activity or boosting cell proliferation. But only one phase is focused during the wound healing process. As a result, there is a need for optimum wound dressing materials that promotes different wound healing cascades with ideal properties. Herein, Graphene Oxide loaded with vanadium (V) doped titanium dioxide (TiO2) blended with chitosan, and polyvinyl alcohol (CS/PVA/GO/TiO2-V) patch was developed for wound healing. XRD, FTIR and FE-SEM analyses were carried out to study the morphology and structural property of the patch. The fabricated patch has a high surface porosity, excellent moisture vapor transfer rate, appropriate swelling behaviour, and oxygen permeability, which results in an excellent moist environment for wound breathing and effective management of wound exudates. The antibacterial test showed significant antibacterial efficacy against wound infections in the presence of light when compared to dark. In-vitro analysis such as hemocompatibility, cytotoxicity, cell adhesion, and scratch assay show the predicted potential wound healing application with high biocompatibility. These results suggest that CS/PVA/GO/TiO2-V patch provides a microenvironment favourable to cells' growth and differentiation and positively modulates full-thickness wounds' healing.


Asunto(s)
Antibacterianos/química , Quitosano/química , Grafito/química , Alcohol Polivinílico/química , Titanio/química , Vanadio/química , Cicatrización de Heridas/efectos de los fármacos , Animales , Antibacterianos/farmacología , Vendajes , Línea Celular , Femenino , Humanos , Luz , Masculino , Ratones , Células 3T3 NIH , Nanoestructuras/química , Porosidad , Ratas , Ratas Wistar , Óxido de Zinc/química
11.
Chemosphere ; 283: 131162, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34157626

RESUMEN

Pyrolysis of agricultural biomass is a promising technique for producing renewable energy and effectively managing solid waste. In this study, groundnut shell (GNS) was processed at 500 °C in an inert gas atmosphere with a gas flow rate and a heating rate of 10 mL/min and 10 °C/min, respectively, in a custom-designed fluidized bed pyrolytic-reactor. Under optimal operating conditions, the GNS-derived pyrolytic-oil yield was 62.8 wt.%, with the corresponding biochar (19.5 wt.%) and biogas yields (17.7 wt.%). The GC-MS analysis of the GNS-based bio-oil confirmed the presence of (trifluoromethyl)pyridin-2-amine (18.814%), 2-Fluoroformyl-3,3,4,4-tetrafluoro-1,2-oxazetidine (16.23%), 5,7-dimethyl-1H-Indazole (11.613%), N-methyl-N-nitropropan-2-amine (6.5%) and butyl piperidino sulfone (5.668%) as major components, which are used as building blocks in the biofuel, pharmaceutical, and food industries. Furthermore, a 2 × 5 × 1 artificial neural network (ANN) architecture was developed to predict the decomposition behavior of GNS at heating rates of 5, 10, and 20 °C/min, while the thermodynamic and kinetic parameters were estimated using a non-isothermal model-free method. The Popescu method predicted activation energy (Ea) of GNS biomass ranging from 111 kJ/mol to 260 kJ/mol, with changes in enthalpy (ΔH), Gibbs-free energy (ΔG), and entropy (ΔS) ranging from 106 to 254 kJ/mol, 162-241 kJ/mol, and -0.0937 to 0.0598 kJ/mol/K, respectively. The extraction of high-quality precursors from GNS pyrolysis was demonstrated in this study, as well as the usefulness of the ANN technique for thermogravimetric analysis of biomass.


Asunto(s)
Redes Neurales de la Computación , Pirólisis , Biomasa , Cinética , Termodinámica , Termogravimetría
12.
Environ Res ; 201: 111429, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34146527

RESUMEN

Effective improvement of an easily recoverable photocatalyst is equally vital to its photocatalytic performance from a practical application view. The magnetically recoverable process is one of the easiest ways, provided the photocatalyst is magnetically strong enough to respond to an external magnetic field. Herein, we prepared graphitic carbon nitride nanosheet (g-C3N4), and ZnS quantum dots (QDs) supported ferromagnetic CoFe2O4 nanoparticles (NPs) as the gC3N4/ZnS/CoFe2O4 nanohybrid photocatalyst by a wet-impregnation method. The loading of CoFe2O4 NPs in the g-C3N4/ZnS nanohybrid resulted in extended visible light absorption. The ferromagnetic g-C3N4/ZnS/CoFe2O4 nanohybrid exhibited better visible-light-active photocatalytic performance (97.11%) against methylene blue (MB) dye, and it was easily separable from the aqueous solution by an external bar magnet. The g-C3N4/ZnS/CoFe2O4 nanohybrid displayed excellent photostability and reusability after five consecutive cycles. The favourable band alignment and availability of a large number of active sites affected the better charge separation and enhanced photocatalytic response. The role of active species involved in the degradation of MB dye during photocatalyst by g-C3N4/ZnS/CoFe2O4 nanohybrid was also investigated. Overall, this study provides a facile method for design eco-friendly and promising g-C3N4/ZnS/CoFe2O4 nanohybrid photocatalyst as applicable in the eco-friendly dye degradation process.


Asunto(s)
Iluminación , Nanocompuestos , Catálisis , Luz , Fotólisis , Sulfuros , Compuestos de Zinc
13.
Chemosphere ; 282: 131103, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34116312

RESUMEN

Alarming water contamination rates by toxic herbicides have drawn attention to treat these pollutants using efficient, easy, and economic techniques. In this work, date-palm coir (DPC) waste-based nano-activated carbon (DPC-AC) was successfully prepared and examined for adsorptive removal of toxic 2,4-dichlorophenoxyacetic acid (2,4-DPA) herbicide from synthetic wastewater. The DPC-AC was synthesized via a single-step carbonization-KOH activation approach. The nanosorbent displayed a flaky morphology with graphitic structure and oxygen-rich surface functionalities. The nanocarbon with a mean particle size of 163 nm possessed a high specific surface area of 947 m2/g with an average pore size of 2.28 nm. High 2,4-DPA removal efficiency of 98.6% was obtained for the optimal adsorption conditions of pH 2, dosage 0.15 g, rotational speed 100 rpm, time 90 min, and initial 2,4-DPA concentration of 100 mg/L. Langmuir isotherm best described the equilibrium behavior with a theoretical maximum of 50.25 mg/g adsorption capacity for the system. Pseudo-second order model was more appropriate in quantifying the kinetics for all initial feed concentrations. Thermodynamically, the adsorption process was spontaneous, endothermic, and involved low activation energy. A plausible mechanism for the adsorption-desorption of 2,4-DPA onto DPC-AC is also discussed. Cost analysis and regenerability studies proved the economic value ($3/kg) and reusable nature of DPC-AC without any significant loss in its performance. Overall, this study highlights the advantages of DPC waste valorization into efficient nanoadsorbent and the sequestration of noxious 2,4-DPA herbicide from its aqueous streams using this nanosorbent.


Asunto(s)
Herbicidas , Phoeniceae , Contaminantes Químicos del Agua , Ácido 2,4-Diclorofenoxiacético , Adsorción , Carbón Orgánico , Concentración de Iones de Hidrógeno , Cinética , Lignina/análogos & derivados , Termodinámica , Contaminantes Químicos del Agua/análisis
14.
Environ Res ; 200: 111428, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34107284

RESUMEN

Atrazine is a toxic herbicide whose alarming rate of contamination in the drinking water and wastewater poses a severe threat to the environment and human health. Here in this study, the graphene oxide (GO) nanosheets were prepared using Hummers' method with minor modification and studied as a potential adsorbent for atrazine removal from simulated wastewater. The spectroscopy and microscopic analysis confirmed the successful formation of GO with a multilayer structure resembling the crumpled sheets with random stacking. The Response Surface Methodology (RSM) employing Box Behnken design (BBD) was successfully developed to predict the optimal conditions for maximal atrazine removal as adsorbent dosage 121.45 mg/L; initial feed concentration 27.03 mg/L; temperature 27.69 °C, pH 5.37, and time 180 min. The atrazine adsorption onto GO was found to be higher in acidic pH and lower temperature. Density functional theory (DFT) calculation of adsorbent-adsorbate complex in the implicit solvent medium suggests adsorption affinity energy of -24.4 kcal/mol for atrazine. A careful observation of the molecules configuration and binding energy showed that the π-π interactions and hydrogen bonds played a significant role in the adsorption phenomena. Langmuir isotherm suited well to the adsorption process with a maximum adsorption capacity of 138.19 mg/g, at 318 K. The fitness of kinetic models for atrazine adsorption onto GO nanosheets were in following order Ho < Sobkowsk-Czerwi < Avrami model based on their correlation coefficient (R2) values. Reusability analysis showed that GO nanosheets could be effectively recycled using 0.01 N NaOH up to six cycles of atrazine removal. Thus, this study provided a theoretical and experimental basis for the potential application of GO nanosheets as a novel adsorbent for the removal of hazardous atrazine.


Asunto(s)
Atrazina , Contaminantes Químicos del Agua , Adsorción , Teoría Funcional de la Densidad , Grafito , Humanos , Concentración de Iones de Hidrógeno , Cinética , Contaminantes Químicos del Agua/análisis
15.
ACS Appl Mater Interfaces ; 13(21): 24643-24653, 2021 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-34008951

RESUMEN

Electrochemical hydrogenation is a challenging technoeconomic process for sustainable liquid fuel production from biomass-derived compounds. In general, half-cell hydrogenation is paired with water oxidation to generate the low economic value of O2 at the anode. Herein, a new strategy for the rational design of Ru/reduced graphene oxide (Ru/RGO) nanocomposites through a cost-effective and straightforward microwave irradiation technique is reported for the first time. The Ru nanoparticles with an average size of 3.5 nm are well anchored into the RGO frameworks with attractive nanostructures to enhance the furfural's paired electrohydrogenation (ECH) and electrooxidation (ECO) process to achieve high-grade biofuel. Furfural is used as a reactant with the paired electrolyzer to produce furfuryl alcohol and 2-methylfuran at the cathode side. Simultaneously, 2-furic acid and 5-hydroxyfuroic acid along with plenty of H+ and e- are generated at the anode side. Most impressively, the paired electrolyzer induces an extraordinary ECH and ECO of furfural, with the desired production of 2-methylfuran (yield = 91% and faradic efficiency (FE) of 95%) at XFF = 97%, outperforming the ECH half-cell reaction. The mechanisms of the half-cell reaction and paired cell reaction are discussed. Exquisite control of the reaction parameters, optimized strategies, and the yield of individual products are demonstrated. These results show that the Ru/RuO nanocomposite is a potential candidate for biofuel production in industrial sectors.

16.
Environ Res ; 197: 111110, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33864793

RESUMEN

Capacitive deionization (CDI) is an evolving technology for eradicating salt and toxic heavy metal ions from brackish wastewater. However, traditional CDI electrodes have lower salt adsorption capacity and inadequate adsorption of selective metal ions for long-term operations. Herein, Ag nanospheres incorporated pomegranate peel-derived activated carbon (Ag/P-AC) was prepared and implied to the CDI process for removing NaCl, toxic mono-, di-, and trivalent metal ions. Morphological analysis revealed that the 80-100 nm-sized Ag nanospheres were uniformly decorated on the surfaces of P-AC nanosheets. The Ag/P-AC has a higher specific surface area (640 m2 g-1), superior specific capacitance (180 F g-1 at 50 mV s-1) and a lower charge transfer resistance (0.5 Ω cm2). CDI device was fabricated by Ag/P-AC as an anode, which adsorbed anions and P-AC as cathode for adsorption of positively charged ions at 1.2 V in an initial salt concentration of 1000 mg L-1. An asymmetric Ag/P-AC//P-AC exhibited a maximum NaCl adsorption capacity of 36 mg g-1 than symmetric P-AC//P-AC electrodes (22.7 mg g-1). Furthermore, Pb(II), Cd(II), F-, and As(III) ions were successfully removed from simulated wastewater by using Ag/P-AC//P-AC based CDI system. These asymmetric CDI-electrodes have an excellent prospect for the removal of salt and toxic contaminants in industrial wastewater.


Asunto(s)
Nanosferas , Granada (Fruta) , Purificación del Agua , Carbón Orgánico , Electrodos , Iones , Plata , Cloruro de Sodio
17.
Environ Pollut ; 281: 116990, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33812129

RESUMEN

The synergistic photoelectrochemical (PEC) technology is a robust process for the conversion of CO2 into fuels. However, designing a highly efficient UV-visible driven photoelectrocatalyst is still challenging. Herein, a plasmonic Ag NPs modified TiO2/RGO photoelectrocatalyst (Ag-TiO2/RGO) has been designed for the PEC CO2 reduction into selective production of CH3OH. HR-TEM analysis revealed that Ag and TiO2 NPs with average sizes of 4 and 7 nm, respectively, were densely grown on the few-micron-sized 2D RGO nanosheets. The physicochemical analysis was used to determine the optical and textural properties of the Ag-TiO2/RGO nanohybrids. Under VU-Vis light illumination, Ag-TiO2/RGO photocathode possessed a current density of 23.5 mA cm-2 and a lower electrode resistance value of 125 Ω in CO2-saturated 1.0 M KOH-aqueous electrolyte solution. Catalytic studies showed that the Ag-TiO2/RGO photocathode possessed a remarkable PEC CO2 reduction activity and selective production of CH3OH with a yield of 85 µmol L-1 cm-2, the quantum efficiency of 20% and Faradic efficiency of 60.5% at onset potential of -0.7 V. A plausible PEC CO2 reduction mechanism over Ag-TiO2/RGO photocathode is schematically demonstrated. The present work gives a new avenue to develop high-performance and stable photoelectrocatalyst for PEC CO2 reduction towards sustainable liquid fuels production.


Asunto(s)
Contaminantes Ambientales , Nanopartículas del Metal , Atmósfera , Dióxido de Carbono , Grafito , Metanol , Plata , Titanio
18.
Int J Cardiol Heart Vasc ; 32: 100701, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33426268

RESUMEN

BACKGROUND: The Ace polymorphism had shown association with ACE activity, premature atherosclerosis, myocardial infarction, LV dysfunction, LV remodelling, severity and extent of CAD and mortality after MI. Though ACE I/D polymorphism has been reported to be associated with various cardiovascular diseases it remained a controversial risk factor and studies have presented conflicting results. This study was designed to determine the association between ACE) gene insertion/deletion (I/D) polymorphism, ACE activity and acute STEMI in Indian population and to determine its influence on outcome after acute MI. MATERIALS AND METHODS: We investigated 934 patients diagnosed with acute STEMI who underwent thrombolysis. ACE I/D polymorphism was detected by polymerase chain reaction and ACE activity was measured in 615 patients. RESULTS: The prevalence of DD, ID, and II genotypes in our study group were 41.97%, 34.36%, and 23.66% respectively. The ACE polymorphism was not significantly associated with the type of myocardial infarction, the LV ejection fraction, the number of vessels diseased and patency of the vessel after thrombolysis. The polymorphism had no influence on in hospital mortality (P = 0.453). The ACE activity also showed no influence on in hospital mortality (P = 0.482). The age > 60 years, Male gender, occluded artery and severe LV dysfunction (LVEF < 35%) were predictors of in-hospital mortality on multivariate regression analysis. CONCLUSION: There was no differences among ACE (I/D) polymorphism observed in STEMI population. Neither ACE I/D polymorphism nor ACE activity predicted in-hospital mortality inpatients admitted with acute STEMI.

19.
J Hazard Mater ; 409: 124980, 2021 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-33418290

RESUMEN

In recent years, substantial progress has been made towards developing effective catalysts for the hydrogenation of CO2 into fuels. However, the quest for a robust catalyst with high activity and stability still remains challenging. In this study, we present a cost-effective catalyst composed of MoS2 nanosheets and functionalized porous date seed-derived activated carbon (f-DSAC) for hydrogenation of CO2 into formic acid (FA). As-fabricated MoS2/f-DSAC catalysts were characterized by FE-SEM, XRD, Raman, FT-IR, BET, and CO2-TPD analyses. At first, bicarbonate (HCO3-) was successfully converted into FA with a high yield of 88% at 200 °C for 180 min under 10 bar H2 atmosphere. A possible reaction pathway for the conversion of HCO3- into FA is postulated. The catalyst has demonstrated high activity and long-term stability over five consecutive cycles. Additionally, MoS2/f-DSAC catalyst was effectively used for the conversion of gaseous CO2 into FA at 200 °C under 20 bar (CO2/H2 = 1:1) over 15 h. The catalyst exhibited a remarkable TOF of 510 h-1 with very low activation energy of 12 kJ mol-1, thus enhancing the catalytic conversion rate of CO2 into FA. Thus, this work demonstrates the MoS2/f-DSAC nanohybrid system as an efficient non-noble catalyst for converting CO2 into fuels.

20.
J Hazard Mater ; 402: 123560, 2021 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-32759001

RESUMEN

Production of multi-functional zinc oxide nanoparticles (ZnO-NPs) for wastewater treatment through green-approaches is a desirable alternative for conventional synthesis routes. Biomass waste valorization for nanoparticles synthesis has received increased research attention. The present study reports date pulp waste (DPW) utilization as an effective bio-reductant for green-synthesis of ZnO-NPs. A simple and eco-friendly process with low reaction time and calcination temperature was adopted for DPW mediated ZnO-NPs (DP-ZnO-NPs) synthesis. Microscopic investigations of DP-ZnO-NPs confirmed the non-agglomeration and spherical nature of particles with mean diameter of 30 nm. EDX and XPS analysis defined the chemical composition and product purity of DP-ZnO-NPs. UV and photoluminescence studies exhibited surface plasmonic resonance at 381 nm and fluorescent nature of DP-ZnO-NPs. FTIR studies established a formation mechanism outline for DP-ZnO-NPs. XRD and Raman investigations confirmed the crystalline and hexagonal wurtzite phase of DP-ZnO-NPs. DSC/TG analysis displayed the thermal stability of DP-ZnO-NPs with <10 wt% loss upto 700 °C. Photocatalytic degradation of hazardous methylene blue and eosin yellow dyes using DP-ZnO-NPs, showed rapid decomposition rate with 90 % degradation efficiency. Additionally, DP-ZnO-NPs demonstrated significant antibacterial effects on various pathogenic bacteria in terms of zone-of-inhibition measured by disc-diffusion method. Thus, the as-prepared DP-ZnO-NPs is suitable for industrial wastewater treatment.


Asunto(s)
Nanopartículas del Metal , Nanopartículas , Phoeniceae , Purificación del Agua , Óxido de Zinc , Antibacterianos , Tecnología Química Verde , Pruebas de Sensibilidad Microbiana
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