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1.
Angew Chem Int Ed Engl ; : e202404401, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38729917

RESUMO

It is a crucial role for enhancing the power conversion efficiency (PCE) of perovskite solar cells (PSCs) to prepare high-quality perovskite films, which can be achieved by delaying the crystallization of perovskite film. Hence, we designed difluoroacetic anhydride (DFA) as an additive to regulating crystallization process thus reducing defect formation during perovskite film formation. It was found DFA reacts with DMSO by forming two molecules, difluoroacetate thioether ester (DTE) and difluoroacetic acid (DA). The strong bonding DTE⋅PbI2 and DA⋅PbI2 retard perovskite crystallization process for high-quality film formation, which was monitored through in situ UV/Vis and PL tests. By using DFA additives, we prepared perovskite films with high-quality and low defects. Finally, a champion PCE of 25.28 % was achieved with excellent environmental stability, which retained 95.75 % of the initial PCE after 1152 h at 25 °C under 25 % RH.

2.
Anal Chim Acta ; 1306: 342615, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38692795

RESUMO

The Caco-2 cells were used as intestinal epithelial cell model to illustrate the hyperuricemia (HUA) mechanism under the co-culture of the imbalanced intestinal microbiome in this work. The uric acid (UA) concentration in the HUA process was monitored, and could be up to 425 µmol/L at 8 h co-cultured with the imbalanced intestinal microbiome. Single-cell potentiometry based on ion-selective microelectrode was used to study extracellular calcium change, which is hypothesized to play an important role in the UA excretion. The potential signal of the calcium in the extremely limited microenvironment around single Caco-2 cell was recorded through the single-cell analysis platform. The potential signal of sharp decrease and slow increase followed within a few seconds indicates the sudden uptake and gradually excretion process of calcium through the cell membrane. Moreover, the value of the potential decrease increases with the increase of the time co-cultured with the imbalanced intestinal microbiome ranging from 0 to 8 h. The Ca2+ concentration around the cell membrane could decrease from 1.3 mM to 0.4 mM according to the potential decrease of 27.0 mV at the co-culture time of 8 h. The apoptosis ratio of the Caco-2 cells also exhibits time dependent with the co-culture of the imbalanced intestinal microbiome, and was 39.1 ± 3.6 % at the co-culture time of 8 h, which is much higher than the Caco-2 cells without any treatment (3.9 ± 2.9 %). These results firstly provide the links between the UA excretion with the apoptosis of the intestinal epithelial cell under the interaction of the imbalanced intestinal microbiome. Moreover, the apoptosis could be triggered by the calcium signaling.


Assuntos
Microbioma Gastrointestinal , Análise de Célula Única , Análise de Célula Única/instrumentação , Análise de Célula Única/métodos , Células CACO-2 , Humanos , Microeletrodos , Técnicas de Cocultura/instrumentação , Técnicas de Cocultura/métodos , Cálcio/análise , Fibra de Carbono , Intestinos/microbiologia , Potenciometria/instrumentação , Adenosina/análise , Apoptose
3.
Adv Mater ; 36(23): e2312014, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38380583

RESUMO

Perovskite photovoltaics have emerged as the most promising candidates for next-generation light-to-electricity technology. However, their practical application still suffers from energy loss induced by intrinsic defects within the perovskite lattice. Here, a refined defect passivation in perovskite films is designed, which shows a multi-interaction mechanism between the perovskite and passivator. Interestingly, a shift of molecular bonding is observed upon cooling down the film, leading to a stronger passivation of iodine/formamidine vacancies. Such mechanism on device under low-light and low-temperature conditions is further leveraged and a record efficiency over 45% with durable ambient stability (T90 > 4000 h) is obtained. The pioneer application of perovskite solar cells in above dual extreme conditions in this work reveals the key principles of designing functional groups for the passivators, and also demonstrates the capability of perovskites for diverse terrestrial energy conversion applications in demanding environments such as polar regions and outer space.

4.
Angew Chem Int Ed Engl ; 62(41): e202309398, 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37624069

RESUMO

Photovoltaic technology with low weight, high specific power in cold environments, and compatibility with flexible fabrication is highly desired for near-space vehicles and polar region applications. Herein, we demonstrate efficient low-temperature flexible perovskite solar cells by improving the interfacial contact between electron-transport layer (ETL) and perovskite layer. We find that the adsorbed oxygen active sites and oxygen vacancies of flexible tin oxide (SnO2 ) ETL layer can be effectively decreased by incorporating a trace amount of titanium tetrachloride (TiCl4 ). The effective defects elimination at the interfacial increases the electron mobility of flexible SnO2 layer, regulates band alignment at the perovskite/SnO2 interface, induces larger perovskite crystal growth, and improves charge collection efficiency in a complete solar cell. Correspondingly, the improved interfacial contact transforms into high-performance solar cells under one-sun illumination (AM 1.5G) with efficiencies up to 23.7 % at 218 K, which might open up a new era of application of this emerging flexible photovoltaic technology to low-temperature environments such as near-space and polar regions.

5.
Adv Mater ; 35(42): e2305314, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37652150

RESUMO

Understanding and controlling crystallization is crucial for high-quality perovskite films and efficient solar cells. Herein, the issue of defects in formamidinium lead iodide (FAPbI3 ) formation is addressed, focusing on the role of intermediates. A comprehensive picture of structural and carrier evolution during crystallization is demonstrated using in situ grazing-incidence wide-angle X-ray scattering, ultraviolet-visible spectroscopy and photoluminescence spectroscopy. Three crystallization stages are identified: precursors to the δ-FAPbI3 intermediate, then to α-FAPbI3 , where defects spontaneously emerge. A hydrogen-sulfate-based ionic liquid additive is found to enable the phase-conversion pathway of precursors → solvated intermediates → α-FAPbI3 , during which the spontaneous generation of δ-FAPbI3 can be effectively circumvented. This additive extends the initial growth kinetics and facilitates solvent-FA+ ion exchange, which results in the self-elimination of defects during crystallization. Therefore, the improved crystallization dynamics lead to larger grain sizes and fewer defects within thin films. Ultimately, the improved perovskite crystallization dynamics enable high-performance solar cells, achieving impressive efficiencies of 25.14% at 300 K and 26.12% at 240 K. This breakthrough might open up a new era of application for the emerging perovskite photovoltaic technology to low-temperature environments such as near-space and polar regions.

6.
Adv Mater ; 35(51): e2303384, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37572021

RESUMO

Upscalable printing of high-performance and stable perovskite solar cells (PSCs) is highly desired for commercialization. However, the efficiencies of printed PSCs lag behind those of their lab-scale spin-coated counterparts owing to the lack of systematic understanding and control over perovskite crystallization dynamics. Here, the controlled crystallization dynamics achieved using an additive 1-butylpyridine tetrafluoroborate (BPyBF4 ) for high-quality ambient printed α-formamidinium lead triiodide (FAPbI3 ) perovskite films are reported. Using in situ grazing-incidence wide-angle X-ray scattering and optical diagnostics, the spontaneous formation of α-FAPbI3 from precursors during printing without the involvement of  Î´-FAPbI3 is demonstrated. The addition of BPyBF4 delays the crystallization onset of α-FAPbI3 , enhances the conversion from sol-gel to perovskite, and reduces stacking defects during printing. Therefore, the altered crystallization results in fewer voids, larger grains, and less trap-induced recombination loss within printed films. The printed PSCs yield high power conversion efficiencies of 23.50% and 21.60% for a 0.09 cm-2 area device and a 5 cm × 5 cm-area module, respectively. Improved device stability is further demonstrated, i.e., approximately 94% of the initial efficiency is retained for over 2400 h under ambient conditions without encapsulation. This study provides an effective crystallization control method for the ambient printing manufacture of large-area high-performance PSCs.

7.
Sci Adv ; 9(35): eadh2255, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37647409

RESUMO

Preliminary theoretical analyses indicate that lattice relaxation may be used to release lattice strain in the FAPbI3 perovskite to warrant both high x-ray detection performance and improved stability. Herein, we demonstrate stable black α-phase FAPbI3 single crystals (SCs) realized by lattice engineering via annealing in the ambient atmosphere. The engineered α-FAPbI3 SC detector shows almost all the best figures of merit including a high sensitivity of 4.15 × 105 µC Gyair-1 cm-2, a low detection limit of 1.1 nGyair s-1, a high resolution of 15.9 lp mm-1, and a short response time of 214 µs. We further demonstrate high-definition x-ray imaging at a dose rate below 10 nGyair s-1 on the FAPbI3 SC, indicating a minimal dose-area product of 0.048 mGyair cm2 to the patient for one-time posteroanterior chest diagnosis, which is more than 3000 times lower than the international reference level of 150 mGyair cm2. In addition, the robust long-term stability enables the FAPbI3 SC x-ray detector to work steadily for more than 40 years.

8.
RSC Adv ; 13(31): 21414-21420, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37465577

RESUMO

The simple and sensitive detection of miRNA-122 in blood is crucially important for early hepatocellular carcinoma (HCC) diagnosis. In this work, a platinum microelectrode (PtµE) was prepared and electrodeposited with molybdenum disulfide (MoS2) and gold nanoparticles (AuNP), respectively, and denoted as PtµE/MoS2/Au. The prepared PtµE/MoS2/Au was used as the microsensor for the detection of miRNA-122 combined with the probe DNA as a biorecognition element which is the complementary strand of miRNA-122. The PtµE/MoS2/Au conjugated with the probe DNA modified with sulfydryl units was used as the micro-biosensor for the detection of miRNA-122. The square wave voltammetry was performed for the quantitative detection of miRNA-122 using [Fe(CN)6]4-/3- as a mediator. Under the optimized conditions, the PtµE/MoS2/Au micro-biosensor shows a linear detection toward miRNA-122 ranging from 10-11 to 10-8 M (S = 6.9 nA dec-1, R2 = 0.9997), and the detection limit is 1.6 × 10-12 M (3σ/b). The PtµE/MoS2/Au micro-biosensor demonstrates good selectivity against other types of proteins and small molecules, and has good reproducibility. Moreover, the PtµE/MoS2/Au micro-biosensor was successfully applied for the measurement of miRNA-122 in real blood samples. Herein, the proposed detection assay could be a potential tool in HCC clinical diagnostics with high sensitivity.

9.
Front Bioeng Biotechnol ; 11: 1159498, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37064219

RESUMO

Introduction: In addition to many cellular processes, Ca2+ is also involved in tumor initiation, progression, angiogenesis, and metastasis. The development of new tools for single-cell Ca2+ measurement could open a new avenue for cancer therapy. Methods: The all-solid-state calcium ion-selective microelectrode (Ca2+-ISµE) based on carbon fiber modified with PEDOT (PSS) as solid-contact was developed in this work, and the characteristics of the Ca2+-ISµE have also been investigated. Results: The Ca2+-ISµE exhibits a stable Nernstian response in CaCl2 solutions in the active range of 1.0 × 10-8 - 3.1 × 10-3 M with a low detection limit of 8.9 × 10-9 M. The Ca2+-ISµE can be connected to a patch clamp to fabricate a single-cell analysis platform for in vivo calcium monitoring of a single renal carcinoma cell. The calcium signal decreased significantly (8.6 ± 3.2 mV, n = 3) with severe fluctuations of 5.9 ± 1.8 mV when the concentration of K+ in the tumor microenvironment is up to 20 mM. Discussion: The results indicate a severe cell response of a single renal carcinoma cell under high K+ stimuli. The detection system could also be used for single-cell analysis of other ions by changing different ion-selective membranes with high temporal resolution.

10.
Chem Commun (Camb) ; 58(79): 11139-11142, 2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36106578

RESUMO

Electrostatically assembled ultrathin rhodium nanosheet-gold nanowire nanocomposites (Rh-Au CNSs) were used as an advanced electrocatalyst for the methanol oxidation reaction, which revealed a mass activity of 355 mA mgRh-1 at 0.607 V potential, much higher than single metal Rh nanosheets (273 mA mgRh-1) and commercial Rh nanoparticles (165 mA mgRh-1).

11.
Anal Biochem ; 658: 114916, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36130652

RESUMO

The detection of tumor markers in blood samples with high efficiency and sensitivity is in urgent need. In this work, a one-step quantitative detection assay for alpha fetal protein (AFP) based on gold microelectrode which is denoted as AuµE through square wave voltammetry using [Fe(CN)6]3-/4- as mediator was developed. As the biorecognition element of the assay, sulfydryl-modified AFP aptamer could be directly conjugated onto the surface of the AuµE, which could capture AFP with high specificity, and this attachment would cause the decrease of the capacitive current of the cyclic voltammetry due to the reduction of the active area of the electrodes. Under the optimized conditions, the AuµE aptasensor exhibited a linear detection range for AFP from 10-10 to 10-7 g/mL (S = 7.6 nA/dec, R2 = 0.991), and the detection limit is 2.5 × 10-11 g/mL. The AuµEs aptasensor demonstrates good selectivity against other types of proteins and small molecules, and has good reproducibility. The real blood samples were used for detection of AFP using the AuµEs aptasensor, the results agree well with those provided by the hospital through electrochemiluminescence method. Herein, the proposed one-step detection assay has a great application potential in point-of-care clinical diagnostics.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Nanopartículas Metálicas , Ouro , alfa-Fetoproteínas , Técnicas Eletroquímicas/métodos , Técnicas Biossensoriais/métodos , Microeletrodos , Reprodutibilidade dos Testes , Eletrodos , Limite de Detecção
12.
Front Chem ; 10: 899276, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35795222

RESUMO

Rapid and highly sensitive detection of carcinoembryonic antigen (CEA) in blood could effectively improve the diagnostic sensitivity of colorectal cancer. In this work, a platinum microelectrode (PtµE) modified with gold nanoparticles was developed as a microsensor for the detection of CEA. As the recognition element, a CEA aptamer modified with sulfhydryl could be conjugated onto the surface of the PtµEs/Au. The quantitative analysis of the concentration of CEA [CEA] by the prepared PtµEs/Au aptasensor was carried out through square wave voltammetry. Under the optimized conditions, the PtµEs/Au aptasensor exhibits a linear response toward [CEA] in the range of 1.0 × 10-11-1.0 × 10-7 g/ml (S = 5.5 nA/dec, R 2 = 0.999), and the detection limit is 7.7 × 10-12 g/ml. The PtµEs/Au aptasensor also has good selectivity against other types of proteins existing in blood. The availability of the developed assay toward [CEA] in blood samples was investigated, and the results agreed well with those obtained through electrochemiluminescence provided by the hospital, and the volume of the blood sample for detection is only 20 µl. Herein, the proposed detection system could be used for the quantitative analysis of CEA in blood, with the advantages of high sensitivity, short time, and low cost. Moreover, the PtµEs/Au aptasensor has a potential application in clinical diagnosis.

13.
Rev. bras. med. esporte ; 28(3): 228-231, May-June 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1365711

RESUMO

ABSTRACT Introduction: It is common for athletes to have accidental injuries in training. Sports injuries damage the health of athletes, dampen their enthusiasm, and affect their normal life and training. Objective: To explore preventive measures against athletes' sports injuries by understanding their sports injuries. Methods: We used the literature data method, a questionnaire, an interview, and mathematical statistics to determine the cause of sports injury accidents of athletes. Results: The locations of sports injuries were fingers, ankle and knee joints, lower back, thighs, etc. Common types of injuries were joint sprains, muscle strains, and soft tissue injuries. Conclusion: Scientific physical training can prevent sports injuries and effectively reduce injuries and accidents caused by sports. Level of evidence II; Therapeutic studies - investigation of treatment results.


RESUMO Introdução: Não é raro que atletas tenham ferimentos acidentais em seus treinamentos. Lesões esportivas causam danos à saúde dos atletas e reduzem seu entusiasmo, afetando suas vidas normais e seu treino. Objetivo: Explorar medidas preventivas contra lesões esportivas para compreender como tais ferimentos ocorrem. Métodos: Este trabalho utilizou pesquisa bibliográfica, questionário, entrevista, e cálculo estatístico matemático para determinar a causa das lesões esportivas acidentais de atletas. Resultados: As lesões esportivas ocorreram em dedos, articulações de tornozelo e joelho, região lombar, coxas e etc. Tipos comuns de lesão incluíram torção de articulações, estiramento muscular, e feridas em tecidos moles. Conclusão: O treino físico com base científica pode prevenir lesões esportivas e efetivamente reduzir os ferimentos e acidentes causados pelo esporte. Nível de evidência II; Estudos terapêuticos - investigação de resultados de tratamento.


RESUMEN Introducción: No es raro que los deportistas sufran lesiones accidentales en sus entrenamientos. Lesiones deportivas causan daños a la salud de los atletas y reducen su entusiasmo, afectando sus vidas normales y su entrenamiento. Objetivo: Explorar medidas preventivas contra lesiones deportivas para comprender cómo tales heridas ocurren. Métodos: Este trabajo utilizó investigación bibliográfica, cuestionario, entrevista y cálculo estadístico matemático pata determinar la causa de las lesiones deportivas accidentales de atletas. Resultados: Las lesiones deportivas ocurrieron en los dedos, articulaciones de los tobillos y rodillas, región lumbar, muslos, etc. Entre los tipos de lesiones más comunes se encuentran los esguinces articulares, las distensiones musculares y las heridas en los tejidos blandos. Conclusión: El entrenamiento físico con base científica puede prevenir lesiones deportivas y efectivamente reducir las heridas y accidentes causados por el deporte. Nivel de evidencia II; Estudios terapéuticos - investigación de resultados de tratamiento.

14.
Data Brief ; 41: 107949, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35242931

RESUMO

These data contain the details of the fabrication of the calcium ion-selective microelectrode (Ca2+-ISµEs) modified with poly(3,4-ethylenedioxythiophene)-poly(sodium 4-styrenesulfonate) (PEDOT(PSS)) as solid contact. The electrochemical impedance spectroscopy was carried out for the investigation of the resistance of the Ca2+-ISµEs. The thickness of the solid contact and the calcium ion-selective membrane was investigated by SEM. Potential-time curve of the electrodeposition of the PEDOT/PSS film onto the surface of the microelectrodes under the applied current of 0.5 µA for 200 s was recorded. The proposed Ca2+-ISµE was optimized through conditioning in different CaCl2 solutions ranged from 1.0 × 10-6 to 3.1 × 10-3 M for different time before use. The anti-fouling property of the Ca2+-ISµEs against proteins was investigated through taking BSA as the model protein. The developed Ca2+-ISµEs were used for the in vivo monitoring of the calcium ions in rat cerebrospinal fluid under the stimuli of the spinal cord transection in a living animal.

15.
Anal Chim Acta ; 1191: 339209, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35033241

RESUMO

Acupuncture needles are regarded as ideal materiel for the development of microelectrodes for in vivo sensing. In this work, an all-solid-state ion-selective microelectrode (ISµE) has been developed by coating a calcium ion-selective membrane on an acupuncture needle tip with a diameter of less than 80 µm, which is modified with poly(3,4-ethylenedioxythiophene)-poly(sodium 4-styrenesulfonate) as solid contact. The proposed Ca2+-ISµE shows a Nernstian response toward Ca2+ in the range from 1.0 × 10-6 to 3.1 × 10-3 M with a slope of 30.8 ± 0.9 mV/decade (R2 = 0.999), and the detection limit is 1.2 × 10-7 M. The Ca2+-ISµE has been used for in vivo monitoring of the calcium changes in rat cerebrospinal fluid (CSF) under the injury of spinal cord transection. The results demonstrate that the calcium concentration in CSF increases sharply from the normal level of 20.6 ± 1.72 µM (n = 3) to 133.2 ± 7.63 µM (n = 3) with a severe fluctuation after spinal cord damage. Thus, the proposed Ca2+-ISµE is available for in vivo monitoring of calcium ions with high temporal resolution and flexibility. The detection system can be extended to measure other ions in CSF by changing different ion-selective membranes.


Assuntos
Terapia por Acupuntura , Cálcio , Animais , Íons , Microeletrodos , Agulhas , Ratos
16.
ACS Appl Mater Interfaces ; 13(38): 45521-45527, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34541852

RESUMO

The nitrate electroreduction reaction (NO3--ERR) is an efficient and green approach for nitrate remediation, which requires a highly active and selective electrocatalyst. In this work, porous and amorphous cobalt phosphide nanoshuttles (CoP PANSs) are successfully synthesized by using Mg2+ ion-doped calcium carbonate nanoshuttles (Mg-CaCO3 NSs) as the initial reaction precursor via precipitation transformation and a high-temperature phosphidation strategy. Various physical characterizations show that CoP PANSs have porous architecture, amorphous crystal structure, and big surface area. Electrochemical measurements reveal for the first time that CoP PANSs have outstanding electroactivity for NO3--ERR in a neutral electrolyte. At an applied potential of -0.5 V vs reversible hydrogen electrode, CoP PANSs can achieve a high Faraday efficiency (94.24 ± 2.8%) and high yield rate (19.28 ± 0.53 mg h-1 mgcat-1) for ammonia production, which exceeds most reported values at various electrocatalysts for NO3--ERR. Thus, the present result indicates that cobalt phosphide nanomaterials have promising application for NO3--ERR.

17.
ACS Appl Mater Interfaces ; 12(14): 16592-16600, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32216332

RESUMO

Lead halide perovskites with good optoelectronic properties and high attenuation of high-energy radiation are great candidates for X-ray radiation detectors. Large area, dense, and thick films or wafers are a prerequisite for these applications. In this paper, a one-step heat-assisted high-pressure press method is developed to directly prepare a large (the largest has a diameter of 80 mm) and thickness- and shape-controlled phase-pure organic-inorganic hybrid CH3NH3PbI3 wafer of densely packed large microcrystals from raw powder materials. Meanwhile, this method uses no solvent to achieve essentially 100% material utilization. The obtained wafers show good ambipolar carrier mobilities of ∼20 cm2 V-1 s-1 and a µτ product as high as 3.84 × 10-4 cm2 V-1. Under an X-ray source using an acceleration voltage of 40 kV, the perovskite wafer-based X-ray detector shows an X-ray sensitivity as large as 1.22 × 105 µC Gyair-1 cm-2 under a 10 V bias, the highest reported for any perovskite material. The method provides a convenient strategy for producing large perovskite wafers with good optoelectronic properties, which will facilitate the development of large perovskite devices.

18.
Nanoscale ; 11(28): 13477-13483, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31287477

RESUMO

Direct ethanol fuel cells (DEFCs) with a high conversion efficiency are quite promising candidates for energy conversion devices. Herein, we have successfully synthesized PdCo alloy nanocubes supported on carbon nanobowl (denoted as Pd2Co1/CNB) nanohybrids by using the cyanogel auto-reduction method at high temperature. The morphology, composition and structure of Pd2Co1/CNB nanohybrids are characterized in detail, revealing that PdCo nanocubes have a high alloying degree and special {110} facets. In cyclic voltammetry measurements, Pd2Co1/CNB nanohybrids show a mass activity of 1089.0 A g Pd-1 and a specific activity of 40.03 mA cm-2 for ethanol electrooxidation at peak potential, which are much higher than that of the commercial Pd/C electrocatalyst (278.2 A gPd-1 and 8.22 mA cm-2). Additionally, chronoamperometry measurements show that Pd2Co1/CNB nanohybrids have excellent durability for ethanol electrooxidation. A high alloying degree, special {110} facets and the CNB supporting material contribute to the high activity and durability of Pd2Co1/CNB nanohybrids, making them a highly promising Pt-alternative electrocatalyst for ethanol electrooxidation in DEFCs.

19.
Opt Express ; 27(10): 14221-14230, 2019 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-31163874

RESUMO

The control of the emission from electric and magnetic dipoles is highly desired for the development of optic chips. Although the emission of electric dipole has been successfully controlled by plasmonic nanoantenna, the control of magnetic dipole emission is relatively difficult. Here, we systematically study the effect of electric and magnetic modes of Au nanocups on the emission of electric and magnetic dipoles. The emission of electric dipole can be enhanced by both the electric and magnetic mode of the Au nanocup, while the emission of the magnetic dipole is only increased by the magnetic mode. The enhancement exhibits wavelength dependence. The wavelength of the largest enhancement is determined by the resonance wavelength of electric and magnetic modes. The enhancement values for electric and magnetic dipoles are determined by the near-field electric and magnetic field enhancements, respectively. More importantly, the emission pattern of magnetic dipole is greatly modified by the magnetic mode of Au nanocup. The directional emission of magnetic dipole is first time realized by use of the magnetic mode of the Au nanocup. Our findings deepen the understanding of the plasmon-controlled emission of electric and magnetic dipoles and will be very helpful to the development of the nanophotonic chips.

20.
Anal Chim Acta ; 1073: 39-44, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31146834

RESUMO

Methods for in-situ measurements of heavy metal ions in coastal sediment pore water to elucidate fine-scale biogeochemical and environmental processes are highly required but have rarely been reported. In this work, an all-solid-state lead-selective microelectrode (Pb2+-ISµE) based on a poly(3,4-ethylenedioxythiophene)-poly(sodium 4-styrenesulfonate) (PEDOT/PSS) modified gold wire with a diameter of 14 µm has been fabricated. The proposed Pb2+-ISµE is capable of in-situ measurement of Pb2+ in coastal sediment pore water at millimeter depth intervals. The Pb2+-ISµE shows a Nernstian response for Pb2+ within the activity range of 2.1 × 10-9-2.1 × 10-4 M (S = 28.1 ±â€¯1.3 mV/dec, R2 = 0.998) in 0.5 M NaCl, and the detection limit is 6.4 × 10-10 M. By lowering the microelectrode into a coastal sediment core with a micro-manipulator, the proposed Pb2+-ISµE allows the direct measurement of the vertical distribution profile of Pb2+ in the pore water. The in-situ measurement of Pb2+ using the microsensor could avoid the problems of sample handling. Moreover, the detection system can be extended to assess the vertical distribution profiles of other heavy metal ions in sediment pore water by using different ion-selective microelectrodes.

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