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1.
J Environ Manage ; 365: 121683, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38963968

RESUMEN

Ammonia recovery from wastewater has positive environmental benefits, avoiding eutrophication and reducing production energy consumption, which is one of the most effective ways to manage nutrients in wastewater. Specifically, ammonia recovery by membrane distillation has been gradually adopted due to its excellent separation properties for volatile substances. However, the global optimization of direct contact membrane distillation (DCMD) operating parameters to maximize ammonia recovery efficiency (ARE) has not been attempted. In this work, three key operating factors affecting ammonia recovery, i.e., feed ammonia concentration, feed pH, and DCMD running time, were identified from eight factors, by a two-level Plackett-Burman Design (PBD). Subsequently, Box-Behnken design (BBD) under the response surface methodology (RSM) was used to model and optimize the significant operating parameters affecting the recovery of ammonia though DCMD identified by PBD and statistically verified by analysis of variance (ANOVA). Results showed that the model had a high coefficient of determination value (R2 = 0.99), and the interaction between NH4Cl concentration and feed pH had a significant effect on ARE. The optimal operating parameters of DCMD as follows: NH4Cl concentration of 0.46 g/L, feed pH of 10.6, DCMD running time of 11.3 h, and the maximum value of ARE was 98.46%. Under the optimized conditions, ARE reached up to 98.72%, which matched the predicted value and verified the validity and reliability of the model for the optimization of ammonia recovery by DCMD process.

2.
Angew Chem Int Ed Engl ; 63(17): e202319529, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38443734

RESUMEN

Limited triple-phase boundaries arising from the accumulation of solid discharge product(s) in solid-state cathodes (SSCs) pose a challenge to high-property solid-state lithium-oxygen batteries (SSLOBs). Light-assisted SSLOBs have been gradually explored as an ingenious system; however, the fundamental mechanisms of the SSCs interface behavior remain unclear. Here, we discovered that light assistance can enhance the fast inner-sphere charge transfer in SSCs and regulate the discharge products with spherical particles generated via the surface growth model. Moreover, the high photoelectron excitation and transportation capabilities of SSCs can retard cathodic catalytic decay by avoiding structural degradation of the cathode with a reduced charge voltage. The light-induced SSLOBs exhibited excellent stability (170 cycles) with a low discharge-charge polarization overpotential (0.27 V). Furthermore, transparent SSLOBs with exceptional flexibility, mechanical stability, and multiform shapes were fabricated for theory-to-practical applications in sunlight-induced batteries. Our study opens new opportunities for the introduction of solar energy into energy storage systems.

3.
Int J Phytoremediation ; 25(9): 1155-1164, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36355569

RESUMEN

In this study, we explored the potential of a newly prepared nano-zero valent zinc (nZVZn), biochar (BC)/nZVZn and BC/hydroxyapatite-alginate (BC/HA-alginate) composites for the removal of inorganic As species from water. Relatively, higher percentage removal of As(III) and As(V) was obtained by nZVZn at pH 3.4 (96% and 94%, respectively) compared to BC/nZVZn (90% and 88%) and BC/HA-alginate (88% and 80%) at pH 7.2. Freundlich model provided the best fit (R2 = up to 0.98) for As(III) and As(V) sorption data of all the sorbents, notably for nZVZn. The pseudo-second order model well-described kinetics of As(III) and As(V) (R2 = 0.99) sorption on all the sorbents. The desorption experiments demonstrated that the As removal efficiency, up to the third sorption/desorption cycle, was in the order of nZVZn ∼ BC/HA-alginate (88%) > BC/nZVZn (84%). The Fourier transform infrared spectroscopy depicted that the -OH, -COOH, Zn-O and Zn-OH surface functional groups were responsible for the sorption of As(III) or As(V) on the sorbents investigated here. This study highlights that removal of As species from water by BC/nZVZn composite can be compared with nZVZn, suggesting that integrating BC with nZVZn could efficiently remove As from As-contaminated drinking water.


This is the first study to explore the potential of a newly prepared sugarcane bagasse biochar/nano-zerovalent zinc (BC/nZVZn) based composite for the removal of inorganic arsenic (As) species from water. The results indicated high percentage removal of As(III) and As(V) from water by BC/nZVZn that were comparable to nZVZn alone.


Asunto(s)
Arsénico , Contaminantes Químicos del Agua , Purificación del Agua , Zinc , Contaminantes Químicos del Agua/química , Adsorción , Purificación del Agua/métodos , Biodegradación Ambiental , Carbón Orgánico/química , Agua , Cinética
4.
Angew Chem Int Ed Engl ; 59(8): 3244-3251, 2020 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-31814233

RESUMEN

We report a straightforward strategy to design efficient N doped porous carbon (NPC) electrocatalyst that has a high concentration of easily accessible active sites for the CO2 reduction reaction (CO2 RR). The NPC with large amounts of active N (pyridinic and graphitic N) and highly porous structure is prepared by using an oxygen-rich metal-organic framework (Zn-MOF-74) precursor. The amount of active N species can be tuned by optimizing the calcination temperature and time. Owing to the large pore sizes, the active sites are well exposed to electrolyte for CO2 RR. The NPC exhibits superior CO2 RR activity with a small onset potential of -0.35 V and a high faradaic efficiency (FE) of 98.4 % towards CO at -0.55 V vs. RHE, one of the highest values among NPC-based CO2 RR electrocatalysts. This work advances an effective and facile way towards highly active and cost-effective alternatives to noble-metal CO2 RR electrocatalysts for practical applications.

5.
Angew Chem Int Ed Engl ; 58(34): 11779-11784, 2019 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-31225687

RESUMEN

In this study, mechanical vibration is used for hydrogen generation and decomposition of dye molecules, with the help of BiFeO3 (BFO) square nanosheets. A high hydrogen production rate of ≈124.1 µmol g-1 is achieved under mechanical vibration (100 W) for 1 h at the resonant frequency of the BFO nanosheets. The decomposition ratio of Rhodamine B dye reaches up to ≈94.1 % after mechanical vibration of the BFO catalyst for 50 min. The vibration-induced catalysis of the BFO square nanosheets may be attributed to the piezocatalytic properties of BFO and the high specific surface area of the nanosheets. The uncompensated piezoelectric charges on the surfaces of BFO nanosheets induced by mechanical vibration result in a built-in electric field across the nanosheets. Unlike a photocatalyst for water splitting, which requires a proper band edge position for hydrogen evolution, such a requirement is not needed in piezocatalytic water splitting, where the band tilting under the induced piezoelectric field will make the conduction band of BFO more negative than the H2 /H2 O redox potential (0 V) for hydrogen generation.

6.
Chem Soc Rev ; 46(5): 1427-1463, 2017 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-28165079

RESUMEN

High-temperature solid oxide electrolysis cells (SOECs) are advanced electrochemical energy storage and conversion devices with high conversion/energy efficiencies. They offer attractive high-temperature co-electrolysis routes that reduce extra CO2 emissions, enable large-scale energy storage/conversion and facilitate the integration of renewable energies into the electric grid. Exciting new research has focused on CO2 electrochemical activation/conversion through a co-electrolysis process based on the assumption that difficult C[double bond, length as m-dash]O double bonds can be activated effectively through this electrochemical method. Based on existing investigations, this paper puts forth a comprehensive overview of recent and past developments in co-electrolysis with SOECs for CO2 conversion and utilization. Here, we discuss in detail the approaches of CO2 conversion, the developmental history, the basic principles, the economic feasibility of CO2/H2O co-electrolysis, and the diverse range of fuel electrodes as well as oxygen electrode materials. SOEC performance measurements, characterization and simulations are classified and presented in this paper. SOEC cell and stack designs, fabrications and scale-ups are also summarized and described. In particular, insights into CO2 electrochemical conversions, solid oxide cell material behaviors and degradation mechanisms are highlighted to obtain a better understanding of the high temperature electrolysis process in SOECs. Proposed research directions are also outlined to provide guidelines for future research.

7.
Phys Chem Chem Phys ; 18(28): 18665-9, 2016 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-27350564

RESUMEN

A new type of Fe, N-doped hierarchically porous carbons (N-Fe-HPCs) has been synthesized via a cost-effective synthetic route, derived from nitrogen-enriched polyquaternium networks by combining a simple silicate templated two-step graphitization of the impregnated carbon. The as-prepared N-Fe-HPCs present a high catalytic activity for the oxygen reduction reaction (ORR) with onset and half-wave potentials of 0.99 and 0.86 V in 0.1 M KOH, respectively, which are superior to commercially available Pt/C catalyst (half-wave potential 0.86 V vs. RHE). Surprisingly, the diffusion-limited current density of N-S-HPCs approaches ∼7.5 mA cm(-2), much higher than that of Pt/C (∼5.5 mA cm(-2)). As a cathode electrode material used in Zn-air batteries, the unique configuration of the N-Fe-HPCs delivers a high discharge peak power density reaching up to 540 mW cm(-2) with a current density of 319 mA cm(-2) at 1.0 V of cell voltage and an energy density >800 Wh kg(-1). Additionally, outstanding ORR durability of the N-Fe-HPCs is demonstrated, as evaluated by the transient cell-voltage behavior of the Zn-air battery retaining an open circuit voltage of 1.48 V over 10 hours with a discharge current density of 100 mA cm(-2).

8.
Chem Soc Rev ; 44(21): 7484-539, 2015 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-26050756

RESUMEN

Electrolytes have been identified as some of the most influential components in the performance of electrochemical supercapacitors (ESs), which include: electrical double-layer capacitors, pseudocapacitors and hybrid supercapacitors. This paper reviews recent progress in the research and development of ES electrolytes. The electrolytes are classified into several categories, including: aqueous, organic, ionic liquids, solid-state or quasi-solid-state, as well as redox-active electrolytes. Effects of electrolyte properties on ES performance are discussed in detail. The principles and methods of designing and optimizing electrolytes for ES performance and application are highlighted through a comprehensive analysis of the literature. Interaction among the electrolytes, electro-active materials and inactive components (current collectors, binders, and separators) is discussed. The challenges in producing high-performing electrolytes are analyzed. Several possible research directions to overcome these challenges are proposed for future efforts, with the main aim of improving ESs' energy density without sacrificing existing advantages (e.g., a high power density and a long cycle-life) (507 references).

9.
Chem Soc Rev ; 43(2): 631-75, 2014 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-24186433

RESUMEN

This paper reviews recent progress made in identifying electrocatalysts for carbon dioxide (CO2) reduction to produce low-carbon fuels, including CO, HCOOH/HCOO(-), CH2O, CH4, H2C2O4/HC2O4(-), C2H4, CH3OH, CH3CH2OH and others. The electrocatalysts are classified into several categories, including metals, metal alloys, metal oxides, metal complexes, polymers/clusters, enzymes and organic molecules. The catalyts' activity, product selectivity, Faradaic efficiency, catalytic stability and reduction mechanisms during CO2 electroreduction have received detailed treatment. In particular, we review the effects of electrode potential, solution-electrolyte type and composition, temperature, pressure, and other conditions on these catalyst properties. The challenges in achieving highly active and stable CO2 reduction electrocatalysts are analyzed, and several research directions for practical applications are proposed, with the aim of mitigating performance degradation, overcoming additional challenges, and facilitating research and development in this area.

10.
Chem Soc Rev ; 42(13): 5768-87, 2013 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-23640049

RESUMEN

In this review, we examine the most recent progress and research trends in the area of alkaline polymer electrolyte membrane (PEM) development in terms of material selection, synthesis, characterization, and theoretical approach, as well as their fabrication into alkaline PEM-based membrane electrode assemblies (MEAs) and the corresponding performance/durability in alkaline polymer electrolyte membrane fuel cells (PEMFCs). Respective advantages and challenges are also reviewed. To overcome challenges hindering alkaline PEM technology advancement and commercialization, several research directions are then proposed.

11.
J Colloid Interface Sci ; 658: 1016-1024, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38160124

RESUMEN

Electrochemical conversion of carbon dioxide (CO2) into syngas is considered a promising approach to mitigate global warming and achieve the recycling of carbon resources. In this work, a series of core-shell metal (copper/indium) oxides with abundant grain boundaries (GBs) between the amorphous In2O3 and cubic Cu2O have been prepared by template-assisted co-precipitation method and tested for the synthesis of syngas by electrochemical CO2 reduction reaction (CO2RR). The phases of Cu2O and In2O3 are independent in bimetallic oxides and do not form any alloy oxidation phase, thus Cu2O and In2O3 can maintain their crystal structure and chemical properties in bimetallic oxides. The Cu2O and In2O3 would been completely reduced to metallic Cu and In during CO2RR. The derived copper/indium possesses the maximum FE of CO (80 %) at -0.77 V vs. reversible hydrogen electrode (RHE) and a good stability of 10 h in an H-type cell. Further applied the copper/indium oxide in the MEA reactor, the FE of CO is more than 80 % at 2.6 V and the total FE of syngas is near 100 % at all applied potentials. More importantly, the H2/CO ratios can be tuned from 1/1 to 1/4 by changing the applied voltages in MEA. Therefore, this study provides a promising strategy to promote the electrocatalytic CO2RR conversion by creating abundant grain boundaries in bimetallic oxides to regulate the ratio of H2/CO.

12.
Foods ; 13(4)2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38397607

RESUMEN

This study investigated the impact of chitosan (CH, 1%) and aloe vera gel (AL, 30%) edible coatings on the preservation of blue honeysuckle quality during a 28-day storage at -1 °C. Coating with CH, AL, and CH+AL led to notable enhancements in several key attributes. These included increased firmness, total soluble solids, acidity, pH, and antioxidant capacity (measured through DPPH, ABTS, and FRAP assays), as well as the preservation of primary (ascorbic acid) and secondary metabolites (TPC, TAC, and TFC). The TAC and TFC levels were approximately increased by 280% and 17%, respectively, in coated blue honeysuckle after 28 d compared to uncoated blue honeysuckle. These coatings also resulted in reduced weight loss, respiration rate, color, abscisic acid, ethylene production, and malondialdehyde content. Notably, the CH+AL treatment excelled in preserving secondary metabolites and elevating FRAP-reducing power, demonstrating a remarkable 1.43-fold increase compared to the control after 28 days. Overall, CH+AL exhibited superior effects compared to CH or AL treatment alone, offering a promising strategy for extending the shelf life and preserving the quality of blue honeysuckle during storage.

13.
J Colloid Interface Sci ; 669: 927-934, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38754145

RESUMEN

Rational construction of efficient bifunctional catalysts with robust catalytic activity and durability is significant for overall water splitting (conversion between water and hydrogen fuel/oxygen) using non-precious metal systems. In this work, the hierarchically porous N, P, O-doped transition metal phosphate in the Ni foam (NF) electrode (hollow flower-like NPO/NixPy@NF) was prepared through facile hydrothermal method coupled with phosphorization treatment. The hierarchical hollow flower-like NPO/NixPy@NF electrodes exhibited high bifunctional activity and stability for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solutions. The optimized electrode showed low overpotentials of 76 and 240 mV for HER and OER to reach a current density of 10 mA cm-2, respectively. Notably, the NPO/NixPy@NF electrode only required a low voltage of 1.99 V to reach the current densities of 100 mA cm-2 with long-term stability for overall water splitting using the NPO/NixPy@NF|| NPO/NixPy@NF cell, surpassing that of the Pt/C-RuO2 (2.24 V@ 100 mA cm-2). The good catalytic and battery performance should be attributed to i) the open hierarchical structure that enhanced the mass transfer; ii) a highly conductive substrate that accelerated the electron transfer; iii) the rich heterojunction and strong synergy between Ni2P and Ni5P4 that improved the catalytic kinetic; iv) the proper-thickness amorphous phosphorus oxide nitride (PON) shell that realized the stability. This work demonstrates a promising methodology for designing bifunctional transition metal phosphides with high performance for efficient water splitting.

14.
J Colloid Interface Sci ; 672: 32-42, 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38824686

RESUMEN

The alkaline solid-state electrolytes have received widespread attention for their good safety and electrochemical stability. However, they still suffer from low conductivity and poor mechanical properties. Herein, we report the synthesis of double-network featured hydroxide-conductive membranes fabricated by polyvinyl alcohol (PVA) and chitosan (CS) as the double-skeletons. Then, we implanted quaternary ammonium salt guar hydroxypropyltrimonium chloride (GG) as the OH- conductor for high-performance electrochemical devices. By virtue of the unique stripe-like structure shared from the double skeleton with a high degree of compatibility and stronger hydrogen bond interactions, the polyvinyl alcohol/chitosan-guar hydroxypropyltrimonium chloride (PCG) solid-state electrolytes achieved optimal thermal stability (> 300 °C), mechanical property (∼ 34.15 MPa), dimensional stability (at any bending angle), and high ionic conductivity (13 mS cm-1) and ion mobility number (tion âˆ¼ 0.90) compared with chitosan-guar hydroxypropyltrimonium chloride (CG) and polyvinyl alcohol-guar hydroxypropyltrimonium chloride (PG) electrolyte membrane. As a proof-of-concept application, the "sandwich"-type zinc-air battery (ZAB) assembled using PCG membrane as the electrolyte realized a high open-circuit voltage (1.39 V) and an excellent power density (128 mW cm-2). Notably, in addition to its long-term cycle life (30 h, 2 mA cm-2) and stable discharge plateau (12 h, 5 mA cm-2), it could even enable a flexible ZAB (F-ZAB) to readily power light-emitting diodes (LED) at any bending angle. These merits afford the PCG membrane a promising electrolyte for improving the performance of solid-state batteries.

15.
Food Chem ; 427: 136605, 2023 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-37390741

RESUMEN

In this paper, the structures of polyphenols and their bioactivity of black mulberry (Morus nigra L.) cv. 'Heisang No. 1' were comprehensively analyzed. The 11 anthocyanins and 20 non-anthocyanin phenolic compounds were identified and quantified by liquid chromatography high-resolution time-of-flight mass spectrometry (LC-HR-TOF/MS2). The cyanidin-3-glucoside and cyanidin-3-rutinoside were the major anthocyanins in the black mulberry. In addition, the black mulberry showed potent antioxidant capacity as assessed by DPPH, ABTS, and FRAP assays. Black mulberry anthocyanins exhibited stronger inhibition activities against α-amylase, α-glucosidase, and lipase compared to non-anthocyanin polyphenols, with IC50 values of 1.10, 4.36, and 9.18 mg/mL, respectively. The total anthocyanin content of black mulberry crude extracts and anthocyanins was 570.10 ± 77.09 and 1278.23 ± 117.60 mg C3GE/100 g DW, respectively. Black mulberry may be a rich source of polyphenols, natural antioxidants, and effective antidiabetic substances with great potential in the food industry.


Asunto(s)
Morus , Polifenoles , Polifenoles/análisis , Antocianinas/análisis , Antioxidantes/química , Morus/química , Fenoles/análisis , Frutas/química , Extractos Vegetales/química
16.
Heliyon ; 9(4): e14685, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37035373

RESUMEN

Blue honeysuckle is a source of anthocyanins with great potential as a food colorant, and a healthy and functional food material, and contains much cyanidin 3-glucoside (C3G), which has many benefits for human health. A rapid, reliable, accurate quantification method of anthocyanin content in different varieties of blue honeysuckle is critical to help in breeding and selecting excellent varieties which are used in the food processing industry and healthcare industry. Our objective was to verify the modified quantification method of C3G and quantified C3G content in three blue honeysuckle varieties of 'Berel', 'Lanjingling' and 'Wulan' using the modified HPLC method by Agilent 1200 system and CAPCELL PAK C18 column (150 mmⅹ4.6 mm, I. D., 5 µm, Japan), with detection at 530 nm, the solvent flow rate was 1 mL/min, the temperature of the column chamber is 35 °C. The results indicated that the modified method was validated in terms of linearity (R2 = 0.999), precision (RSD = 0.61%), stability (RSD = 5.23%), and recovery with a good level, and C3G can be quickly quantified in blue honeysuckle. In addition, 'Wulan' contains the highest C3G level compared with 'Lanjingling' and 'Berel'.

17.
Plant Physiol Biochem ; 204: 108090, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37847973

RESUMEN

Blue honeysuckle (Lonicera caerulea L.) is an emerging commercial fruit in the world, has been known for its multiple anthocyanins in the berries, cyanidin-3-glucoside (C3G) is a major anthocyanin in berries and it makes up 76-92% of the total anthocyanins content, with high antioxidant capacity, and widely used in food products. In this review, recent studies related to anthocyanins in blue honeysuckle were sorted out, including the current status of research on anthocyanins in blue honeysuckle berries, especially C3G, qualitative and quantitative analysis of anthocyanins in berries, extraction and purification methods of anthocyanins from blue honeysuckle, in addition, biological effects of blue honeysuckle, and recommended utilization. Blue honeysuckle contains polyphenols, flavonoids, anthocyanins, minerals, and multiple bioactive compounds, it has been extensively reported to have significant antioxidant, cardioprotective, anti-inflammatory, neuroprotective, anticancer, and anti-diabetic functions, and has been used in a variety of food products as raw materials.


Asunto(s)
Antocianinas , Lonicera , Antocianinas/análisis , Antioxidantes/farmacología , Flavonoides/análisis , Polifenoles/análisis , Frutas/química , Extractos Vegetales
18.
J Colloid Interface Sci ; 606(Pt 2): 994-1003, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34487946

RESUMEN

Electrochemical reduction of CO2 to fuels and chemicals is an effective way to reduce greenhouse gas emissions and alleviate the energy crisis, but the highly active catalysts necessary for this reaction under mild conditions are still rare. In this work, we grew CuBi bimetallic catalysts on derived copper foam substrates by co-electrodeposition, and then investigated the correlation between co-electrodeposition potential and electrochemical performance in CO2-to-formate conversion. Results showed that the bimetallic catalyst formed at a low potential of - 0.6 V vs. AgCl/Ag electrode achieved the highest formate Faradaic efficiency (FEformate) of 94.4% and a current density of 38.5 mA/cm2 at a low potential of - 0.97 V vs. reversible hydrogen electrode (RHE). Moreover, a continuous-flow membrane electrode assembly reactor also enabled the catalyst to show better performance (a FEformate of 98.3% at 56.6 mA/cm2) than a traditional H-type reaction cell. This work highlights the vital impact of co-electrodeposition potential on catalyst performance and provides a basis for the modulated growth of bimetallic catalysts on substrates. It also shows the possibility of preparing Bi-based catalysts with no obvious decrease in catalytic activity that have been partially replaced with more economic copper.

19.
Nanoscale ; 14(5): 2065-2073, 2022 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-35080227

RESUMEN

Exploring high-activity electrocatalysts for an oxygen reduction reaction (ORR) is of great significance for a variety of renewable energy conversion and storage technologies. Here, ultrafine Mo2C nanoparticles assembled in N and P-co-doped carbon (Mo2C@NPC) was developed from ZIF-8 encapsulated molybdenum-based polyoxometalates (PMo12) as a highly efficient ORR electrocatalyst and shows excellent performance for zinc-air batteries. The well distribution of the PMo12 in ZIF-8 results in the formation of ultrafine Mo2C nanocrystallites encapsulated in a porous carbon matrix after pyrolysis. Significantly, from experimental and theoretical investigations, the highly porous structure, highly dispersed ultrafine Mo2C and the N and P co-doping in the Mo2C@NPC lead to the remarkable ORR activity with an onset potential of ∼1.01 V, a half-wave potential of ∼0.90 V and a Tafel slope of 51.7 mV dec-1 at 1600 rpm in 0.1 M KOH. In addition, the Mo2C@NPC as an ORR catalyst in zinc-air batteries achieved a high power density of 266 mW cm-2 and a high specific capacity of 780.9 mA h g-1, exceeding that driven by commercial Pt/C. Our results revealed that the porous architecture and ultrafine Mo2C nanocrystallites of the electrocatalysts could facilitate mass transport and increase the accessibility of active sites, thus optimizing their performances in an ORR. The present study provides some guidelines for the design and synthesis of efficient nanostructured electrocatalysts.

20.
Food Chem ; 385: 132588, 2022 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-35303652

RESUMEN

The structure of proanthocyanidins extracted from bird cherry fruits was characterized by HPLC-ESI/MS2 and MALDI-TOF/MS analyses, and their subunits and mean degree of polymerization (mDP) were investigated by thiolysis reaction, and the inhibition activity against starch hydrolases measured using the high-throughput turbidity assay. This is the first mass spectrometric analysis to thoroughly investigate the structure and mDP of proanthocyanidins in bird cherry fruits. Bird cherry proanthocyanidins were categorized as oligomeric proanthocyanidins (mDP = 5.6), which constituted of (epi)gallocatechins and (epi)catechins. The proanthocyanidins increased from a (epi)gallocatechin-[(epi)catechin]3 tetramer to a (epi)gallocatechin-[(epi)catechin]11 dodecamer through the addition of one (epi)catechin with both A-type and B-type linkages. The proanthocyanidins had potent α-amylase and α-glucosidase inhibition activities with IC50 values of 0.19 ± 0.01 µg/mL and 0.18 ± 0.006 µg/mL, comparing favorably to commercial drug acarbose. Bird cherry oligomeric proanthocyanidins are a promising starch hydrolase inhibitor for the application of potential functional food components.


Asunto(s)
Catequina , Proantocianidinas , Prunus , Catequina/química , Polimerizacion , Proantocianidinas/análisis , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Almidón , alfa-Amilasas
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