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1.
ACS Energy Lett ; 9(4): 1803-1825, 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38633997

RESUMEN

Growing concern regarding the impact of fossil fuels has led to demands for the development of green and renewable materials for advanced electrochemical energy storage devices. Biopolymers with unique hierarchical structures and physicochemical properties, serving as an appealing platform for the advancement of sustainable energy, have found widespread application in the gel electrolytes of supercapacitors. In this Review, we outline the structure and characteristics of various biopolymers, discuss the proposed mechanisms and assess the evaluation metrics of gel electrolytes in supercapacitor devices, and further analyze the roles of biopolymer materials in this context. The state-of-the-art electrochemical performance of biopolymer-based hydrogel electrolytes for supercapacitors and their multiple functionalities are summarized, while underscoring the current technical challenges and potential solutions. This Review is intended to offer a thorough overview of recent developments in biopolymer-based hydrogel electrolytes, highlighting research concerning green and sustainable energy storage devices and potential avenues for further development.

2.
Nano Lett ; 23(22): 10563-10570, 2023 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-37926962

RESUMEN

Efficient oil/water separation tackles various issues in occasions of oil leakage and oil discharge, such as environmental pollution, recollection of the oil, and saving the water. Herein, a compact superhydrophobic/superoleophilic graphitic carbon nitride nanolayer coated on carbon fiber networks (CNBA/CF) is designed and synthesized for efficient gravity-driven oil/water separation. The CNBA/CF shows excellent oil absorption and an impressive oil/water filtration separation performance. The flux reaches the state-of-art value of 4.29 × 105 L/m2/h for dichloromethane with separation efficiency up to 99%. Successive oil absorption tests, long-term filtration separation, and harsh conditions experiments confirm the remarkable separation and chemical structure stability of the CNBA/CF filter. Besides, the CNBA/CF demonstrates good photocatalytic antifouling ability thanks to the extended visible light absorption and improved charge separation. This work combines the material surface wettability modulation with a photocatalytic self-cleaning property in the fabrication of efficient oil/water separation materials while overcoming the filter fouling issue.

3.
J Environ Manage ; 323: 116318, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36261971

RESUMEN

It is well-known that metal corrosion is accelerated by formation of galvanic cell. In this study, we reported the acceleration of denitrification by using conductive carrier through formation of microbial galvanic cell (MGC). Electrically conductive graphite plate (GP) was used as biofilm carrier and compared with the non-conductive polypropylene (PP) plate carrier. Cyclic voltametric analyses showed that biofilms with bidirectional electron transfer functions of bioelectrochemical denitrification (BEDN) and acetate oxidation could be enriched spontaneously onto the GP carrier, hinting the establishment of MGC. Further analysis using differential pulse voltammetry revealed that the redox mediator related to extracellular electron transfer was detected in both media of the GP and PP carrier. Microbial community analysis showed that the biofilms in both GP and PP carrier had identical microbial composition but varied in abundance. The genus of Comamonas, Pseudomonas, Paracoccus and Thauera were the dominance of electroactive denitrifiers responsible for BEDN in both the GP and PP carrier. The GP carrier had a 75.9% higher abundant enrichment of electroactive denitrifiers than the PP carrier. Denitrification performance analyses showed that the GP carrier had a denitrification rate constant (kDN) of 1.25 and 2.66 h-1 at 15 °C and 30 °C, respectively, which was nearly 76.1% and 92.7% higher than the non-conductive PP carrier with corresponding values of about 0.71 and 1.38 h-1. Further, the result of conductive carrier accelerating denitrification was confirmed in scaled-up denitrification bioreactors with volume of 104 L using brush-like biofilm carriers. The acceleration of denitrification was attributed to the spontaneously established MGC, which promoted the direct and mediated electron transfer of the electroactive denitrifiers grown onto the conductive carriers and speeded up the BEDN. The result of this study demonstrated that the BEDN could be integrated to traditional biological denitrification system to accelerate denitrification in the form of MGC by simply employment of conductive carrier.


Asunto(s)
Desnitrificación , Grafito , Polipropilenos , Reactores Biológicos , Biopelículas , Acetatos , Empleo , Nitrógeno/análisis
4.
Biotechnol Bioeng ; 119(1): 268-276, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34698369

RESUMEN

Generally, high bioelectroactivity of anodophilic biofilm favors high power generation of microbial fuel cell (MFC); however, it is not clear whether it can promote denitrification of MFC synchronously. In this study, we studied the impact of anodophilic biofilm bioelectroactivity on the denitrification behavior of air-cathode MFC (AC-MFC) in steady state and found that high bioelectroactivity of anodophilic biofilm not only favored high power generation of the AC-MFC, but also promoted the growth of denitrifers at the anodes and strengthened denitrification. Anodophilic biofilms of AC-MFC with various bioelectroactivity were acclimated at conditions of open circuit (OC), Rext of 1000 Ω and 20 Ω (denoted as AC-MFC-OC, AC-MFC-1000Ω, and AC-MFC-20Ω, respectively) and performed for over 100 days. Electrochemical tests and microbial analysis results showed that the anode of the AC-MFC-20Ω delivered higher current response of both oxidation and denitrification and had higher abundance of electroactive bacteria than the AC-MFC-OC, AC-MFC-1000Ω, demonstrating a higher bioelectroactivity of the anodophilic biofilms. Moreover, these electroactive bacteria favored the accumulation of denitrifers, like Thauera and Alicycliphilus, probably by consuming trace oxygen through catalyzing oxygen reduction. The AC-MFC-20Ω not only delivered a 61.7% higher power than the AC-MFC-1000Ω, but also achieved a stable and high denitrification rate constant (kDN ) of 1.9 h-1 , which was 50% and 40% higher than that of the AC-MFC-OC and AC-MFC-1000Ω, respectively. It could be concluded that the high bioelectroactivity of the anodophilic biofilms not only favored high power generation of the AC-MFC, but also promoted the enrichment of denitrifers at the anodes and strengthened denitrification. This study provided an effective method for enhancing power generation and denitrification performance of the AC-MFC synchronously.


Asunto(s)
Fuentes de Energía Bioeléctrica/microbiología , Biopelículas , Desnitrificación/fisiología , Aire , Electrodos/microbiología
5.
Biosens Bioelectron ; 171: 112685, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33113383

RESUMEN

The spread of SARS-CoV-2 virus in the ongoing global pandemic has led to infections of millions of people and losses of many lives. The rapid, accurate and convenient SARS-CoV-2 virus detection is crucial for controlling and stopping the pandemic. Diagnosis of patients in the early stage infection are so far limited to viral nucleic acid or antigen detection in human nasopharyngeal swab or saliva samples. Here we developed a method for rapid and direct optical measurement of SARS-CoV-2 virus particles in one step nearly without any sample preparation using a spike protein specific nanoplasmonic resonance sensor. As low as 370 vp/mL were detected in one step within 15 min and the virus concentration can be quantified linearly in the range of 0 to 107 vp/mL. Measurements shown on both generic microplate reader and a handheld smartphone connected device suggest that our low-cost and rapid detection method may be adopted quickly under both regular clinical environment and resource-limited settings.


Asunto(s)
Betacoronavirus/aislamiento & purificación , Técnicas Biosensibles/instrumentación , Técnicas de Laboratorio Clínico , Infecciones por Coronavirus/diagnóstico , Neumonía Viral/diagnóstico , Pruebas en el Punto de Atención , Virión/aislamiento & purificación , Anticuerpos Inmovilizados/química , Técnicas Biosensibles/economía , COVID-19 , Prueba de COVID-19 , Técnicas de Laboratorio Clínico/economía , Infecciones por Coronavirus/economía , Diseño de Equipo , Humanos , Límite de Detección , Modelos Moleculares , Pandemias , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/análisis , Factores de Tiempo
6.
Sci Total Environ ; 725: 138508, 2020 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-32302852

RESUMEN

Microbial electro-Fenton system (MEFS) shows potential application for degradation of recalcitrant pollutants. In order to simplify the MEFS and adapt to the practical application situations, such as water, soil or sludge remediation, we developed an automatic MEFS (AMEFS) for degradation of a recalcitrant dye, acid orange 7. The AMEFS contained a microchannel-structured carbon decorated with iron oxides as electro-Fenton cathode. The AMEFS could be either two-electrode configuration that the microchannel-structured carbon connected with an additional bioanode by an external circuit, or single-electrode configuration that the microchannel-structured carbon served as both bioanode and cathode. Thanks to the microchannel structure of the carbon cathode, the AMEFS could be auto-driven by a process similar to the transpiration process of natural plants. The two-electrode AMEFS had higher degradation efficiency of acid orange 7 at lower external resistance, and achieved the highest degradation efficiency of 96% at the short-circuit condition. The single-electrode configuration simplified the setup of the AMEFS and possessed comparable performance with that of two-electrode configuration at short-circuit condition. Moreover, it could degrade high concentration acid orange 7 of up to 50 mg L-1 and achieve a high degradation efficiency of over 93%. The AMEFS could be applied for soil and sludge remediation by direct insertion of the microchannel structured carbon into contaminated body.


Asunto(s)
Peróxido de Hidrógeno , Contaminantes Químicos del Agua/análisis , Compuestos Azo , Bencenosulfonatos , Electrodos , Hierro , Oxidación-Reducción
7.
Sci Total Environ ; 710: 136250, 2020 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-31918188

RESUMEN

Plastics not only bring convenience and color to human life, but also bring endless troubles and disaster to our environment. Reutilization of plastic wastes is in favor of energy conservation and emission reduction, thereby is a significant pathway of plastic wastes disposal. Carbonization is an effective way of converting polymer precursors to valuable carbon materials for use in fields of energy conversion and storage, environmental protection and restoration. Here, we present a systematic multi-perspective overview of carbonization as a feasible route of reutilization of plastic wastes. A brief summary of conventional routes for plastic wastes is followed by a brief introduction of carbonization for converting plastics to carbon materials. Special emphasis is paid on the carbonization pathways and mechanisms of common plastics. Finally, the feasibility, application prospect and challenge of carbonization as one method of reutilization of plastic wastes are proposed. By presenting a consolidated information source on different carbonization mechanisms, this review provides a valuable guideline for reutilization of plastic wastes by carbonization.

8.
Water Environ Res ; 92(7): 997-1005, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31891435

RESUMEN

To achieve deep understandings on the effects of structure and surface properties of anode material on the performance of bioelectrochemical systems, the present research investigated the bacterial community structures of biofilms attached to different three-dimensional anodes including carbon felt and materials derived from pomelo peel, kenaf stem, and cardboard with 454 pyrosequencing analysis based on the bacterial 16S rRNA gene. The results showed that bacterial community structures, especially the relative abundance of exoelectrogens, were significantly related to the types of adopted three-dimensional anode materials. Proteobacteria was the shared predominant phylum, accounting for 55.4%, 52.1%, 66.7%, and 56.1% for carbon felt, cardboard, pomelo peel, and kenaf stem carbon, respectively. The most abundant OTU was phylogenetically related to the well-known exoelectrogen of Geobacter, with a relative abundance of 16.3%, 19.0%, 36.3%, and 28.6% in carbon felt, cardboard, pomelo peel, and kenaf stem, respectively. Moreover, another exoelectrogen of Pseudomonas sp. accounted for 4.9% in kenaf stem and 3.9% in carbonboard, respectively. The results implied the macrostructure and properties of different anode materials might result in different niches such as hydrodynamics and substrate transport dynamics, leading to different bacterial structure, especially different relative abundance of exoelectrogens, which consequently affected the performance of bioelectrochemical systems. PRACTITIONER POINTS: Bioelectrochemical systems (BESs) represent a novel biotechnology platform to simultaneously treat wastewaters and produce electrical power. Three-dimensional materials derived from nature plant as anode to promote electricity output from BESs and reduce the construct cost of BESs. Macrostructure of the three-dimensional anode material affected phylotype richness and phylogenetic diversity of microorganisms in anodic biofilm of BESs. Geobacter as well-known exoelectrogen was the most abundant in biofilm attached to three-dimensional anode.


Asunto(s)
Fuentes de Energía Bioeléctrica , Carbono , Biopelículas , Electrodos , Filogenia , ARN Ribosómico 16S
9.
RSC Adv ; 9(24): 13608-13613, 2019 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-35519595

RESUMEN

The investigation of the draw ratio and velocity of an electrospinning polymer solution jet is of great interest for understanding the formation of nanofibers. During the electrospinning process, the charged polymer solution jets were stretched by electric force, resulting in the formation of ultrathin fibers. In this study, theoretical deduction and experimental calculation were applied to evaluate the velocities and draw ratios of the charged jets at different electrospinning stages. Depending on the diameter of the charged jets at different electrospinning stages, the velocities and draw ratios of the charged jets were calculated with values far lower than the data in a previous report. The theoretical calculation was compared with experimental data using polyamic acid as a model polymer for electrospinning. The results indicated that during electrospinning, as the collecting distance was increased from 0 to 30 cm, the diameter of the electrospinning jet decreased from 18 800 nm to a constant value of around 245 nm, the solvent in the jet decreased from 96.50 wt% to 25.45 wt%, and the density of the jet increased from 0.9504 to 1.0995 g cm-3. These parameters led to the draw ratio and velocity of the jet experiencing first an increase and then a decrease in the value, and the highest draw ratio and velocity were 869 and 867 m s-1, respectively, which are quite different from the data in previous reports.

10.
RSC Adv ; 8(2): 848-855, 2018 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-35539001

RESUMEN

Activated carbon (AC) is an environmentally sustainable oxygen reduction reaction (ORR) catalyst and widely used in MFCs due to its intrinsic high specific surface area and mesoporous characteristics, but it shows relatively high ORR over-potential thus low electrocatalytic activity. In this study, a method of doped carbon modification was employed to decrease the over-potential and improve the ORR electrocatalytic activity of the AC catalyst. Nitrogen and phosphorus co-doped carbon modified AC (NPC@AC) was prepared by coating phytic acid doped polyaniline onto AC through in situ oxidative polymerization and subsequent high-temperature pyrolysis. The as-prepared NPC@AC possessed a large surface area of ∼649.3 m2 g-1 inherited from AC and a low ORR over-potential with a highly positive onset potential of +0.22 V vs. Ag/AgCl from NPC, thus showing an enhanced ORR electrocatalytic activity in neutral solution compared to the pristine AC, and even better than the pure NPC. The air-cathode MFC using the NPC@AC catalyst generated a much higher open circuit voltage of 0.753 V and two times higher power density of 1223 mW m-2 than that using the pristine AC catalyst of about 0.432 V and 595 mW m-2, respectively.

11.
J Mater Chem B ; 6(28): 4610-4617, 2018 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-32254405

RESUMEN

The development of novel materials for facile, cost-effective and quick practical application is a demanding research interest in electroanalytical chemistry. Titanium carbide (TiC), as one of the most important transition metal carbides, exhibits good chemical stability and electrical conductivity, and its electrocatalytic activity resembles that of metals, but is much cheaper. In this work, TiC nanoparticle (NP) loaded carbon nanofiber (CNF) films (TCNFs) are synthesized using an electrospinning and carbothermal technique, which facilely maintains their structural integrity with robust adhesion. Uniform TiC NPs are firmly embedded in the surface of CNFs, which integrates the large surface area and unique 3D, porous network structure of CNFs with the good conductivity and excellent electrocatalytic activity of TiC NPs. Simultaneous electrochemical sensing of ascorbic acid (AA), dopamine (DA) and uric acid (UA) at TCNFs displays excellent peak current signals with well-defined peak potentials. The linear ranges are 0.001-1.5 mM, 0.05-160 µM and 0.001-0.875 mM for AA, DA and UA, and the corresponding detection limits are 0.3 µM, 20 nM and 0.3 µM, respectively. In addition, TCNFs show long-term sensing stability and potential applications in real samples, and behave as good anti-interference agents towards KNO3, ZnSO4, glucose, etc. Most importantly, unlike some common carbon-based electrochemical sensor systems, an adsorption-less response is observed for the test analytes at the TCNF electrode. TCNFs show interesting potential as candidates for the construction of electrochemical sensors.

12.
RSC Adv ; 8(9): 4794-4802, 2018 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-35539515

RESUMEN

Sub-nanometer materials have received wide attention due to their unique properties in recent years. Most studies focus on the preparation and properties investigation of the inorganic sub-nanometer materials, while there are few reports on organic especially polymeric sub-nanometer materials such as sub-nanometer fiber due to the obstacles with respect to fabricating such small nanofibers. In this work we prepare PAA nanofibers with diameters ranging from hundreds of nanometers down to sub-nanometer via electrospinning from a polyamic acid (PAA) with ultrahigh molecular weight. The morphologies and size of the electrospun ultrathin nanofibers are characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). AFM images combined with theoretic calculations show that sub-nanometer fiber of approximate 0.17-0.63 nm only containing one molecular chain was generated via electrospinning from ultra-dilute PAA solutions for the first time. These quite small sub-nanometer fibers would open a new area of electrospinning and provide further explorations on the production and application of electrospun sub-nanometer fibers with single molecular chains.

13.
Sci Rep ; 7(1): 7769, 2017 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-28798334

RESUMEN

In this paper, a novel nitrogen-doped carbon paper (NCP) with both highly dense three-dimensional cellular structure and excellent bending flexibility is fabricated by pyrolyzing a melamine foam under compression. When serving as a free-standing anode for lithium-ion batteries, the NCP electrode delivers a reversible capacity up to 329.8 mA h g-1 after 200 cycles at 0.5 A g-1 (1.34 C) and 126.5 mA h g-1 after 500 cycles at 8.0 A g-1 (21.5 C). Such electrochemical performance is much higher than those of the counterparts prepared by pyrolysis without compression and can be mainly attributed to (a) the 3D highly dense interconnected carbon network with numerous junctions which can facilitate the efficient electron transfer and provide short transportation paths for lithium ions; and (b) the excellent mechanical flexibility and self-standing capability which exempt the use of binder, conductive additive and current collector. The NCP electrode implies a great promise of application in the high-performance Li-ion batteries for the flexible and wearable electronics.

14.
Sci Rep ; 7(1): 1440, 2017 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-28469142

RESUMEN

A hierarchical mesoporous carbon foam (ECF) with an interconnected micro-/mesoporous architecture was prepared and used as a binder-free, low-cost, high-performance anode for lithium ion batteries. Due to its high specific surface area (980.6 m2/g), high porosity (99.6%), light weight (5 mg/cm3) and narrow pore size distribution (~2 to 5 nm), the ECF anode exhibited a high reversible specific capacity of 455 mAh/g. Experimental results also demonstrated that the anode thickness significantly influence the specific capacity of the battery. Meanwhile, the ECF anode retained a high rate performance and an excellent cycling performance approaching 100% of its initial capacity over 300 cycles at 0.1 A/g. In addition, no binders, carbon additives or current collectors are added to the ECF based cells that will increase the total weight of devices. The high electrochemical performance was mainly attributed to the combined favorable hierarchical structures which can facilitate the Li+ accessibility and also enable the fast diffusion of electron into the electrode during the charge and discharge process. The synthesis process used to make this elastic carbon foam is readily scalable to industrial applications in energy storage devices such as li-ion battery and supercapacitor.

15.
ACS Appl Mater Interfaces ; 8(51): 34985-34990, 2016 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-27977119

RESUMEN

The anodophilic bacteria in the anodes of microbial fuel cells (MFCs) used to catalyze carbon oxidation are anaerobes and require anaerobic conditions; their bioelectrocatalytic activity will be greatly suppressed upon direct exposure to O2. In this study, an aerotolerant bioanode was fabricated for the first time by immobilization of anodophilic bacteria for use in MFCs operating under aerobic conditions. The fabrication of the aerotolerant bioanode was realized through the electrochemically induced penetration and propagation of anodophilic bacteria in a three-dimensional hydrogel scaffold. Under the protection of the hydrogel scaffold, the anodophilic bacteria exhibited excellent bioelectrocatalytic activity under continuous O2 aeration and delivered a current density comparable to that under anaerobic conditions. The MFC equipped with the aerotolerant bioanode has the potential to be applied to traditionally aerobic wastewater treatment (WWT) technology. This study offers new insight into the application of MFCs for WWT.

16.
Huan Jing Ke Xue ; 37(6): 2271-2275, 2016 Jun 08.
Artículo en Chino | MEDLINE | ID: mdl-29964896

RESUMEN

Microbial diversity of anodic biofilm in bioelectrochemical systems with hemp rod carbonized at 1000 and 1800℃ as anode was investigated using Solexa high-throughput sequencing technology. The results showed that a total of 4231 and 5263 optimized 16S rRNA gene sequences were gained from the electrode biofilm on the hemp rod carbonized at 1000 and 1800℃, respectively. At the level of 97% similarity, 1187 and 1338 OTUs were obtained for electrode biofilm carbonized at 1000 and 1800℃, respectively. The result of α diversity analysis showed that microbial diversity increased with decreasing carbonization temperature. Dominant phylum for both biofilms were Proteobacteria, Firmicutes and Bacteroidetes, which accounted for 66%, 10% and 9%, respectively for 1000℃, while 71%, 7% and 9%, respectively for 1800℃. Beside the coexisting phylum, some unique species were also discovered, demonstrating that carbonization temperature did not only influence the electrode structure, but also affected the microbial community structure.


Asunto(s)
Bacterias/clasificación , Carbono , Electrodos , Temperatura , Secuenciación de Nucleótidos de Alto Rendimiento , Filogenia , ARN Ribosómico 16S
17.
Anal Chem ; 88(2): 1371-7, 2016 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-26653076

RESUMEN

Effective immobilization of enzymes/proteins on an electrode surface is very essential for biosensor development, but it still remains challenging because enzymes/proteins tend to form close-packed structures on the electrode surface. In this work, nitrogen-doped carbon nanotubes (NCNTs) supported by three-dimensional Kenaf Stem-derived porous carbon (3D-KSC) (denoted as 3D-KSC/NCNTs) nanocomposites were constructed as the supporting matrix to load glucose oxidase (GOD) for preparing integrated glucose biosensors. These NCNTs are vertically arrayed on the channel walls of the 3D-KSC via the chemical vapor deposition method, which could noticeably increase the effective surface area, mechanical stability, and active sites (originating from the doped nitrogen) of the nanocomposites. The integrated glucose biosensor exhibits some advantages over the traditional GOD electrodes in terms of the capability to promote the direct electron transfer of GOD, enhance the mechanical stability of the biosensor attributed to the strong interaction between NCNTs and GOD, and enlarge the specific surface area to efficiently load a large number of GODs. The as-prepared biosensor shows a good performance toward both oxygen reduction and glucose biosensing. This study essentially offers a novel approach for the development of biosensors with excellent analytical properties.


Asunto(s)
Técnicas Biosensibles , Enzimas Inmovilizadas/química , Glucosa Oxidasa/química , Glucosa/análisis , Nanotubos de Carbono/química , Nitrógeno/química , Técnicas Electroquímicas , Enzimas Inmovilizadas/metabolismo , Glucosa/metabolismo , Glucosa Oxidasa/metabolismo , Tamaño de la Partícula , Porosidad , Propiedades de Superficie
18.
J Mater Chem B ; 3(23): 4641-4646, 2015 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-32262478

RESUMEN

The electroactive biofilms in the bioelectrodes of traditional bioelectrochemical systems (BES) directly interact with the aqueous solution and usually require a mild aqueous solution environment (e.g. 20 mM acetate and pH = 7.0) to exert their optimum bioelectrocatalytic activity. In this communication, we present a concept of encapsulation of a bioelectrode by a hydrogel for a BES in an alkaline solution environment. A hydrogel-bioelectrode (HBE) was prepared by encapsulating a living electroactive biofilm pre-grown in the bioelectrode with a poly(vinyl alcohol) hydrogel through a freezing/thawing process. Under the protection of the hydrogel, the HBE could keep a high bioelectrocatalytic activity in an alkaline feeding solution with an acetate concentration of over 80 mM and a pH value of 11.0. Moreover it was very stable and tolerated low-frequency ultrasonic vibration. These results imply the extended applications of BESs in the area of high-strength wastewater treatment, portable and implantable devices.

19.
ScientificWorldJournal ; 2014: 130185, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24883348

RESUMEN

Carbon nanofibers modified graphite fibers (CNFs/GF) composite electrode was prepared for anode in high substrate concentration microbial fuel cells. Electrochemical tests showed that the CNFs/GF anode generated a peak current density of 2.42 mA cm(-2) at a low acetate concentration of 20 mM, which was 54% higher than that from bare GF. Increase of the acetate concentration to 80 mM, in which the peak current density of the CNFs/GF anode greatly increased and was up to 3.57 mA cm(-2), was seven times as that of GF anode. Morphology characterization revealed that the biofilms in the CNFs/GF anode were much denser than those in the bare GF. This result revealed that the nanostructure in the anode not only enhanced current generation but also could tolerate high substrate concentration.


Asunto(s)
Fuentes de Energía Bioeléctrica , Electrodos , Grafito , Nanofibras , Conductividad Eléctrica
20.
Anal Chem ; 86(3): 1414-21, 2014 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-24422469

RESUMEN

A three-dimensional (3D) macroporous carbon (3D-KSCs) derived from kenaf stem (KS) is proposed as a novel supporting material for electrochemical sensing and a biosensing platform. A series of 3D-KSCs/inorganic nanocomposites such as Prussian blue (PB) nanoparticles (NPs)-carboxylic group-functionalized 3D-KSCs (PBNPs-3D-FKSCs), CuNiNPs-3D-KSCs, and CoNPs-3D-KSCs were prepared by a facile two-step route consisting of carbonization and subsequent chemical synthesis or one-step carbonization of KS-metal ion complex. The obtained 3D-KSCs/inorganic nanocomposites were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, scanning electron microscopy, and Fourier transform-infrared spectroscopy. A whole piece of 3D-KSCs/nanocomposites was used to prepare an integrated 3D-KSCs/nanocomposite electrode. Compared to the electrode modified by graphene, carbon nanotubes and their derivatives, which can form close-packed structure after assembled on electrode surface, the integrated 3D-KSCs/nanocomposite electrode shows a 3D honeycomb porous structure. Such structure provides a large specific surface area, effectively supports a large number of electro-active species, and greatly enhances the mass and electron transfer. The electrochemical behaviors and electrocatalytic performances of the integrated 3D-KSCs/inorganic nanocomposite electrode were evaluated by cyclic voltammetry and the amperometric method. The resulted PBNPs-3D-FKSCs, CuNiNPs-3D-KSCs, and CoNPs-3D-KSCs electrode show good electrocatalytic performances toward the reduction of H2O2, the oxidation of glucose and amino acid, respectively. Therefore, the low-cost, renewable, and environmentally friendly 3D-KSCs should be promising supporting materials for an electrochemical sensor and biosensor.


Asunto(s)
Biomasa , Técnicas Biosensibles/métodos , Carbono/química , Acetilcisteína/análisis , Acetilcisteína/química , Electroquímica , Electrodos , Glucosa/análisis , Glucosa/química , Hibiscus/química , Peróxido de Hidrógeno/análisis , Peróxido de Hidrógeno/química , Tallos de la Planta/química , Porosidad
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