Suchergebnisse

Boron/nitrogen, co-doped, carbon nano-onions (BN-CNOs) have recently shown great promise as catalysts for the oxygen reduction reaction, due to the improved electronic properties imparted by the dopant atoms; however, the interactions of BN-CNOs with biological systems have not yet been explored. In this study, we examined the toxicological profiles of BN-CNOs and oxidized BN-CNOs (oxi-BN-CNOs) in vitro in both healthy and cancer cell lines, as well as on the embryonic stages of zebrafish (Danio rerio) in vivo. The cell viabilities of both cell lines cells were not affected after treatment with different concentrations of both doped CNO derivatives. On the other hand, the analysis of BN-CNOs and oxidized BN-CNO interactions with zebrafish embryos did not report any kind of perturbations, in agreement with the in vitro results. Our results show that both doped CNO derivatives possess a high biocompatibility and biosafety in cells and more complex systems. ; This research was supported in part by the Spanish MICINN (project grant PID2019-104739GB-100/AEI/10.13039/501100011033) from the Government of Aragon (project DGA E13-20R). ; Peer reviewed

This article belongs to the Special Issue Luminescence Properties of Nanomaterials and Nanocomposites. ; Band gap engineering of atomically thin two-dimensional (2D) materials has attracted a huge amount of interest as a key aspect to the application of these materials in nanooptoelectronics and nanophotonics. Low-loss electron energy loss spectroscopy has been employed to perform a direct measurement of the band gap in atomically thin MoxW(1−x)S2 nanoflakes. The results show a bowing effect with the alloying degree, which fits previous studies focused on excitonic transitions. Additional properties regarding the Van Hove singularities in the density of states of these materials, as well as high energy excitonic transition, have been analysed as well. ; Research supported by the Spanish MICINN (PID2019-104739GB-100/AEI/10.13039/ 501100011033), Government of Aragon (project DGA E13-20R) and European Union H2020 programs "ESTEEM3" (823717), Graphene Flagship (881603), JST-CREST (JPMJCR20B1, JPMJCR20B5, JPMJCR1993) and JSPS A3 Foresight Program. ; Peer reviewed

1 figure.-- Talk delivered at the HeteroNanoCarb-2019 Conference, Advances and applications in carbon related nanomaterials: From pure to doped structures including heteroatom layers, 2019, December 09th -- 13th, Centro de Ciencias de Benasque Pedro Pascual in Benasque (Aragon, Spain). ; For the last fifteen years, graphene oxide (GO) has become a material of great importance within the subject of chemically modified graphene (CDG) for its vast potential applications. However, both the chemical structure of Graphene oxide and the diverse processes taking place in thermal reduction of GO into reduced graphene oxide (RGO) are still not completely clear despite the sizable amount of studies concerning this issue. TEM and EELS, using a sample holder capable of heating samples up to 1200ºC within the TEM, is a unique and extensive technique for the analysis of the reduction of GO. Using this technique, we can measure, simultaneously and in situ, four main properties essential to this analysis at several intermediate temperatures and under high vacuum: the oxidation rate, its thickness, its mass density and its sp2-sp3 bond ratio. This study presents an analysis of GO by studying all of the aforementioned properties in two different studies: a first one heating up to 300ºC to better understand the physisorbed and chemisorbed water desorption, and a second one up to 1200ºC focused on the desorption of various oxygen functional groups; as well as the graphitisation of GO. Our results will be compared with previous studies on the matter. ; This work was supported by the Spanish MINECO (MAT2016-79776-P, AEI/FEDER, EU), and European Union H2020 programs Marie Sklodowska-Curie Enabling Excellence (642742), ESTEEM3 (823717), Flag-ERA GATES (JTC - PCI2018-093137) and Graphene Flagship (785219).

Laminated metal dichalcogenides are candidates for different potential applications ranging from catalysis to nanoelectronics. However, efforts are still needed to optimize synthesis methods aiming to control the number of layers, morphology, and crystallinity, parameters that govern the properties of the synthesized materials. Another important parameter is the thickness and the length of the samples with the possibility of large-scale growth of target homogeneous materials. Here, we report a chemical vapor deposition method at atmospheric pressure to produce vertically aligned tin dichalcogenide based-materials. Tin disulfide (SnS2) and tin diselenide (SnSe2) vertically aligned nanosheets have been synthesized and characterized by different methods showing their crystallinity and purity. Homogenous crystalline 2H-phase SnS2 nanosheets with high purity were synthesized with vertical orientation on substrates; sulfur vacancies were observed at the edges of the sheets. Similarly, in the crystalline 2H phase SnSe2 nanosheets selenium vacancies were observed at the edges. Moreover, these nanosheets are larger than the SnS2 nanosheets, show lower nanosheet homogeneity on substrates and contamination with selenium atoms from the synthesis was observed. The synthesized nanomaterials are interesting in various applications where the edge accessibility and/or directionality of the nanosheets play a major role as for example in gas sensing or field emission. ; This research work was financed by a grant from the University of Namur. C. Bittencourt and J.-F. Colomer are Research Associates of the National Funds for Scientific Research (FRS-FNRS, Belgium). CB thanks the Belgian Fund for Scientific Research under the FRFC contract CDR J001019. The Electron Microscopy Unit, member of Morph-IM platform from the UNamur, is acknowledged for electron microscopy facilities. The SIAM (Synthesis, Irradiation and Analysis of Matter) and PC2 platforms of the UNamur are acknowledged for XPS and XRD measurements respectively. The STEM measurements were performed in the Laboratorio de Microscopias Avanzadas (LMA) at the Universidad de Zaragoza (Spain). R.A. acknowledges funding from the Spanish MICINN (project grant PID2019-104739GB-100/AEI/10.13039/501100011033), from the Government of Aragon (project DGA E13-17R (FEDER, EU)) and from the European Union H2020 programs "ESTEEM3" (grant number 823717) and "Graphene Flagship – CORE3" (grant number 881603). ; Peer reviewed

Identification of active sites in heterogeneous metal catalysts is critical for understanding the reaction mechanism at the molecular level and for designing more efficient catalysts. Because of their structural flexibility, subnanometric metal catalysts, including single atoms and clusters with a few atoms, can exhibit dynamic structural evolution when interacting with substrate molecules, making it difficult to determine the catalytically active sites. In this work, Pt catalysts containing selected types of Pt entities (from single atoms to clusters and nanoparticles) have been prepared, and their evolution has been followed, while they were reacting in a variety of heterogeneous catalytic reactions, including selective hydrogenation reactions, CO oxidation, dehydrogenation of propane, and photocatalytic H2 evolution reaction. By in situ X-ray absorption spectroscopy, in situ IR spectroscopy, and high-resolution electron microscopy techniques, we will show that some characterization techniques carried out in an inadequate way can introduce confusion on the interpretation of coordination environment of highly dispersed Pt species. Finally, the combination of catalytic reactivity and in situ characterization techniques shows that, depending on the catalyst¿reactant interaction and metal¿support interaction, singly dispersed metal atoms can rapidly evolve into metal clusters or nanoparticles, being the working active sites for those abovementioned heterogeneous reactions. ; This work has been supported by the European Union through the European Research Council (grant ERC-AdG-2014- 671093, SynCatMatch) and the Spanish government through the "Severo Ochoa Program" (SEV-2016-0683). L.L. thanks ITQ for providing a contract. The authors also thank Microscopy Service of UPV for the TEM and STEM measurements. This research used resources of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, and was supported by the U.S. DOE under contract no. DE-AC02-06CH11357 and the Canadian Light Source and its funding partners. The HR STEM and STEM−EELS studies were conducted at the Laboratorio de Microscopias Avanzadas, Universidad de Zaragoza, Spain. R.A. acknowledges support from Spanish MINECO grant MAT2016-79776-P (AEI/FEDER, UE), from the Government of Aragon and the European Social Fund (grant number E13_17R, FEDER, UE), and from the European Union H2020 program "ESTEEM3" (grant number 823717). A.V.P. thanks the Spanish Government (Agencia Estatal de Investigacion) and the European Union (European ́ Regional Development Fund) for a grant for young researchers (CTQ2015-74138-JIN, AEI/FEDER/UE).

We report on the growth of non-stoichiometric nanocrystalline hydroxyapatite (nHAp) with a composition similar to natural bone by a wet-chemical in-situ precipitation route on carbon nanotubes (CNTs) with different degrees of oxygen functionalities and on graphene oxide (GO). Both, functionalization degree and morphology of CNTs and GO appear as critical parameters controlling the shape and crystallinity of the self-assembled nHAp nanoparticles in the corresponding composite materials. Crystalline nHAp nanoparticles with rod-like morphology were achieved for moderately oxidized CNTs and for GO. On CNTs these grow along the CNT's axis while on GO they form a compact layer. In both cases enhanced nHAp integration onto the respective carbon support is obtained. In vitro bioactivity of the prepared composites exhibits a fast apatite biomineralization process, induced by the presence of nHAp. Depending on its crystalline size and dispersion degree remineralization of the apatite nanoparticles takes place through the inclusion of PO4 3 and CO32 by ion exchange. Importantly, during the stage of bioactivity the integration degree of nHAp nanoparticles on the carbon nanostructures alters with time, evidencing the potential of GO as valuable bioceramic support material. ; Spanish Ministry MINECO (project MAT201015026 ; Spanish National Research Council CSIC (project 201080E124, and PhD grant JAEPre09-01155) ; Regional Government of Aragon and the European Social Fund (DGA-ESF-T66 Grupo Consolidado) ; EU COST network MP0901 NanoTP ; EU 7th Framework Program (Grant Agreement 312483-ESTEEM2) ; Peer reviewed

In press ; Owing to their great interest for energy storage and sensing applications, multi-layer papers consisting of graphene oxide – carbon nanotube (GO-CNT) hybrid sheets were prepared by in-situ exfoliation of graphite oxide in the presence of oxidized CNTs (oCNTs). For the first time we elucidate the influence of oCNTs on chemisorbed water (CW), i.e. water molecules inherently bound to oxygen functional groups (OFGs) of graphene oxide (GO) and responsible for irreversible structural damage upon thermal reduction processes. We show that oCNTs self-assemble onto GO sheets during the liquid phase processing steps by forming cooperatively strengthened OH···O=C hydrogen bonds between the carboxylic groups of oCNTs and OFGs of GO. At oCNT contents of about 10 to 15 wt. % this leads to the displacement of considerable amounts of CW without altering the original chemical composition of GO. Thermally reduced GO-CNT (rGO-CNT) papers reveal improved sp2 character and an enhancement of the specific capacitance by 75% with respect to thermally reduced GO (rGO), largely due to the effective removal of CW by oxidized CNTs. These findings disclose the relevance of cooperative hydrogen bonding phenomena in graphene oxide paper/film electrodes for the development of improved electrochemical energy storage and sensing devices. ; JDN is thankful for his CSIC PhD grant JAEPre09-01155 covering also his research stay at Rice University. WKM and AMB acknowledge financial support from Spanish MINECO and the European Regional Development Fund through project grants ENE2013-48816-C5-5-R, ENE2016-79282-C5-1-R and the Government of Aragon and the European Social Fund under project DGA-FSE-T66 CNN. RA gratefully acknowledges the support from MINECO through project grants FIS2013-46159- C3-3-P and MAT2016-79776-P. Some of the research has received funding from the European Union FP7 program under Grant Agreement 312483 ESTEEM2 (Integrated Infrastructure Initiative – I3) and from the European Union H2020 program under the grant 696656 Graphene Flagship, and H2020 Marie Skłodowska-Curie grant 642742. ; Peer reviewed

5 Figuras, 1 Esquema, 1 Tabla .-- Información suplementaria disponible en la página web del editor. ; The preparation of MoS 2 ‐polymer carbon nanodot (MoS 2 ‐PCND) hybrid material was accomplished by employing an easy and fast bottom‐up synthetic approach. Specifically, MoS 2 ‐PCND was realized by the thermal decomposition of ammonium tetrathiomolybdate and the in‐situ complexation of Mo with carboxylic acid units present in the surface of PCNDs. The newly prepared hybrid material was comprehensively characterized by spectroscopic, thermal and electron microscopy imaging means. The electrocatalytic activity of MoS 2 ‐PCND was examined against the hydrogen evolution reaction (HER) and compared with that attributed to the hybrid material prepared by a top‐down approach, namely with MoS 2 ‐PCND(exf‐fun), in which MoS 2 was firstly exfoliated and then covalently functionalized with PCNDs. The MoS 2 ‐PCND hybrid material showed superior electrocatalytic activity against HER with low Tafel slope value and excellent electrocatalytic stability, with an onset potential at ‐0.16 V vs RHE. The superior catalytic performance of MoS 2 ‐PCND was rationalized by considering the catalytic active sites of MoS 2 , the effective charge/energy‐transfer phenomena from PCNDs to MoS 2 and the synergetic effect between MoS 2 and PCNDs within the hybrid material. ; This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 642742. Support of this work by the project "Advanced Materials and Devices" (MIS 5002409) which is implemented under the "Action for the Strategic Development on the Research and Technological Sector", which is implemented under the "Reinforcement of the Research and Innovation Infrastructures", funded by the Operational Program "Competitiveness, Entrepreneurship and Innovation" (NSRF 2014-2020) and co-financed by Ministry of Development and Investments, Greece, and the European Union (European Regional Development Fund) is also acknowledged. A.M.B. and W.K.M. acknowledge Spanish MINEICO (project grant ENE2016-79282-C5-1-R, AEI/FEDER, UE) and the Gobierno de Aragón (Grupo Reconocido DGA T03_17R, FEDER, UE). The SR-EELS studies were conducted at the Laboratorio de Microscopias Avanzadas, Instituto de Nanociencia de Aragon, Universidad de Zaragoza, Spain. The SR-EELS studies were conducted at the Laboratorio de Microscopias Avanzadas, Instituto de Nanociencia de Aragon, Universidad de Zaragoza, Spain. R.A. gratefully acknowledges the support from the Spanish Ministry of Economy and Competitiveness (MINECO) through project grant MAT2016-79776-P (AEI/FEDER, UE) from the Government of Aragon and the European Social Fund under the project "Construyendo Europa desde Aragon" 2014-2020 (grant number E13_17R) and from the European Union H2020 programs "ESTEEM3" (823717) and under the "Graphene Flagship" CORE2 project grant agreement No 785219. ; Peer reviewed

ACS AuthorChoice - This is an open access article published under an ACS AuthorChoice License.-- et al. ; We report the fine-tuning of the localized surface plasmon resonances (LSPRs) from ultraviolet to near-infrared by nanoengineering the metal nanoparticle morphologies from solid Ag nanocubes to hollow AuAg nanoboxes and AuAg nanoframes. Spatially resolved mapping of plasmon resonances by electron energy loss spectroscopy (EELS) revealed a homogeneous distribution of highly intense plasmon resonances around the hollow nanostructures and the interaction, that is, hybridization, of inner and outer plasmon fields for the nanoframe. Experimental findings are accurately correlated with the boundary element method (BEM) simulations demonstrating that the homogeneous distribution of the plasmon resonances is the key factor for their improved plasmonic properties. As a proof of concept for these enhanced plasmonic properties, we show the effective label free sensing of bovine serum albumin (BSA) of single-walled AuAg nanoboxes in comparison with solid Au nanoparticles, demonstrating their excellent performance for future biomedical applications. ; J.A. and A.G. acknowledge the funding from Generalitat de Catalunya 2014 SGR 1638 and Spanish MICINN Project eATOM (MAT2014-51480-ERC). A.G. acknowledges the Turkish Ministry of National Education for the Ph.D. scholarship. J.P., N.G.B., and V.P. acknowledge financial support from the Generalitat de Catalunya 2014-SGR-612, Spanish MICINN (MAT2012-33330), and European Community (EU-FP7) through the FutureNanoNeeds project. N.G.B. thanks the Spanish MICINN for the financial support through the Juan de la Cierva program and European Commission for the Career Integration Grant (CIG)-Marie Curie Action. Some of the research leading to these results has received funding from the European Union Seventh Framework Program under Grant Agreement 312483 - ESTEEM2 (Integrated Infrastructure Initiative − I3). ; Peer Reviewed

The self-assembly of novel core-shell nanoensembles consisting of regioregular poly(3-hexylthiophene) nanoparticles (P3HTNPs) of 100 nm as core and semiconducting CdTe quantum dots (CdTeQDs) as shell with a thickness of a few tens of nanometres was accomplished by employing a re-precipitation approach. The structure, morphology and composition of CdTeQDs/P3HTNPs nanoensembles were confirmed by high-resolution scanning transmission microscopy and dynamic light scattering studies. Intimate interface contact between the CdTeQDs shell and the P3HTNPs core leads to the stabilization of the CdTeQDs/P3HTNPs nanoensemble as probed by steady-state absorption spectroscopy. Effective quenching of the characteristic photoluminescence of CdTeQDs at 555 nm, accompanied by simultaneous increase of emission of P3HTNPs at 660 and 720 nm, reveals photoinduced charge-transfer processes. Probing the redox properties of films of CdTeQDs/P3HTNPs further proves the formation of a stabilized core-shell system in the solid-state. Photoelectrochemical assays on CdTeQDs/P3HTNPs films show a reversible on-off photoresponse at a bias voltage of +0.8 V with a three times increased photocurrent compared to CdTeQDs. The improved charge separation is directly related to the unique core-shell configuration, in which the outer CdTeQDs shell forces the P3HTNPs core to effectively act as electron acceptor. The creation of novel donor-acceptor core-shell hybrid materials via self-assembly is transferable to other types of conjugated polymers and semiconducting nanoparticles. This work, therefore, opens new pathways for the design of improved optoelectronic devices. ; This work has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 642742. AMB and WKM gratefully acknowledge financial support from Spanish MINECO under project ENE206-79282-C5-1-R and its associated European Regional Development Fund, as well as the Government of Aragon under project DGA-T66 and associated European Social Fund. RA gratefully acknowledges financial support from Spanish MINECO under project MAT2016 79776-P and its associated European Regional Development Fund, as well as the Government of Aragon under project DGA-E26 and associated European Social Fund. The STEM studies were conducted at the Laboratorio de Microscopias Avanzadas, Instituto de Nanociencia de Aragon Universidad de Zaragoza, Spain. The authors would like to thank Esteban Urriolabeitía for carrying out the NMR studies. ; Peer reviewed

We present the analysis of a family of nanotubes (NTs) based on the quaternary misfit layered compound (MLC) YxLa1–xS-TaS2. The NTs were successfully synthesized within the whole range of possible compositions via the chemical vapor transport technique. In-depth analysis of the NTs using electron microscopy and spectroscopy proves the in-phase (partial) substitution of La by Y in the (La,Y)S subsystem and reveals structural changes compared to the previously reported LaS-TaS2 MLC-NTs. The observed structure can be linked to the slightly different lattice parameters of LaS and YS. Raman spectroscopy and infrared transmission measurements reveal the tunability of the plasmonic and vibrational properties. Density-functional theory calculations showed that the YxLa1–xS-TaS2 MLCs are stable in all compositions. Moreover, the calculations indicated that substitution of La by Sc atoms is electronically not favorable, which explains our failed attempt to synthesize these MLC and NTs thereof. ; A.E. acknowledges the support by Act 211 Government of the Russian Federation, Contract No. 02.A03.21.0006. The support of the Israel Science Foundation (Grant No. 7130970101), Irving and Cherna Moskowitz Center for Nano and Bio-Nano Imaging, and the Perlman Family Foundation and the Kimmel Center for Nanoscale Science (Grant No. 43535000350000) is greatly acknowledged. R.A. gratefully acknowledges the support from the Spanish Ministry of Economy and Competitiveness (MINECO) through Project Grant MAT2016-79776-P (AEI/FEDER, UE) and from the European Union H2020 program "ESTEEM3" (823717). S.H. acknowledges funding by the German Research Foundation (HE 7675/1-1). I.P. is the incumbent of the Sharon Zuckerman Research Fellow Chair. ; Peer reviewed

The incorporation of plasmonic nanoconstructs in biodegradable polymeric nanoparticles (NPs), together with therapeutic drugs in a controlled procedure is of interest for different applications in Nanomedicine. Advanced hybrid nanomaterials can be engineered by combining the in situ formation of plasmonic palladium nanosheets (NSs) and the proper ionic nature of the encapsulated drug. This study presents a new procedure to synthesize hybrid nanostructures by a Pickering double emulsion. Anisotropic palladium (Pd) NSs with unique near-infrared (NIR)-optical properties can be assembled within a poly lactic-co-glycolic acid matrix of REF: RTI2018-099019-A-I00. R.A. acknowledges funding from the Spanish MICINN (project grant PID2019-104739GB-100/AEI/10.13039/501100011033), from the Government of Aragon (project DGA E13-20R), and from the European Union H2020 program "ESTEEM3" (No. 823717). ; Peer reviewed

5 Figuras.- Información complementaria disponible en línea en la página web del editor ; Carbon nanofoam (CNF) is a low-density, high-surface-area material formed by aggregation of amorphous carbon nanoparticles into porous nanostructures. We report the use of a pulsed infrared laser to prepare CNF from a graphene oxide (GO) target material. Electron microscopy shows that the films consist of dendritic strings that form web-like three-dimensional structures. The conductivity of these structures can be modified by using the CNF as a nanostructured scaffold for gold nanoparticles deposited by sputter coating, controllably increasing the conductivity by up to 4 orders of magnitude. The ability to measure the conductivity of the porous structures allows electrochemical measurements in the environment. Upon decreasing humidity, the pristine CNF exhibits an increase in resistance with a quick response and recovery time. By contrast, the gold-sputtered CNF showed a decrease in resistance, indicating modification of the doping mechanism due to water adsorption. The sensitivity to humidity is eliminated at the percolation threshold of the metal on the CNF. ; Graham Booth's work is highly appreciated, helping to set up the deposition system. This work has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant Agreement 642742 as well as from EU H2020 program "Graphene Flagship" (Grant Agreement 696656). R.A. gratefully acknowledges the support from the Spanish Ministerio de Economia y Competitividad (Grant MAT2016-79776-P, (AEI/FEDER, UE)), from the Government of Aragon and the European Social Fund under the project "Construyendo Europa desde Aragon" 2014–2020 (Grant E/26). A.M.B and W.K.M gratefully acknowledge the financial support from Spanish MINECO and AEI (Project ENE2016-79282-C5-1-R and associated EU Regional Development Funds) and the Gobierno de Aragón (Consolidated Group DGA-T66-GCNN and associated EU Social Funds). S.V.-R. thanks Spanish MINECO for her Ph.D. grant (BES2014-068727 and associated EU Social Funds). ; Peer reviewed

5 Figuras.- Información complementaria disponible en línea en la página web del editor ; Carbon nanofoam (CNF) is a low-density, high-surface-area material formed by aggregation of amorphous carbon nanoparticles into porous nanostructures. We report the use of a pulsed infrared laser to prepare CNF from a graphene oxide (GO) target material. Electron microscopy shows that the films consist of dendritic strings which form web-like three-dimensional structures. The conductivity of these structures can be modified by using the CNF as a nanostructured scaffold for gold nanoparticles deposited by sputter coating, controllably increasing the conductivity by up to four orders of magnitude. The ability to measure the conductivity of the porous structures allows electrochemical measurements in the environment. Upon decreasing humidity, the pristine CNF exhibits an increase in resistance with a quick response and recovery time. By contrast, the gold-sputtered CNF showed a decrease in resistance, indicating modification of the doping mechanism due to water adsorption. The sensitivity to humidity is eliminated at the percolation threshold of the metal on the CNF. ; Graham Booth's work is highly appreciated helping to set up the deposition system. This work has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 642742 as well as for EU H2020 program "Graphene Flagship" (Grant Agreement 696656). R.A. gratefully acknowledges the support from the Spanish Ministerio de Economia y Competitividad (MAT2016-79776-P, (AEI/FEDER, UE)), from the Government of Aragon and the European Social Fund under the project "Construyendo Europa desde Aragon" 2014-2020 (grant number E/26). A.M.B and W.K.M gratefully acknowledge the financial support from Spanish MINECO and AEI (project ENE2016-79282-C5-1-R and associated EU Regional Development Funds), and the Gobierno de Aragón (Consolidated Group DGA-T66-GCNN and associated EU Social Funds). SVR thanks Spanish MINECO for her PhD grant (BES2014-068727 and associated EU Social Funds). ; Peer reviewed