Read by QxMD icon Read


Kevin W Kimura, Kevin E Fritz, Jiyoon Kim, Jin Suntivich, Héctor D Abruña, Tobias Hanrath
We demonstrate a simple strategy to enhance the CO2 reduction reaction (CO2 RR) selectivity by applying a pulsed electrochemical potential to a polycrystalline copper electrode. By controlling the pulse duration, we show that the hydrogen evolution reaction (HER) is highly suppressed to a fraction of the original value (<5 % faradaic efficiency) and selectivity for the CO2 RR dramatically improves (>75 % CH4 and >50 % CO faradaic efficiency). We attribute the improved CO2 RR selectivity to a dynamically rearranging surface coverage of hydrogen and intermediate species during the pulsing...
May 22, 2018: ChemSusChem
Bhawna Nagar, Deepak P Dubal, Luis Pires, Arben Merkoçi, Pedro Gómez-Romero
Inspired by future needs of flexible, simple, and low-cost energy storage devices, smart graphene-based micro-supercapacitors on conventional Xerox paper substrates were developed. The use of redox-active species (iodine redox couple) was explored to further improve the paper device's performance. The device based on printed graphene paper itself already had a remarkable maximum volumetric capacitance of 29.6 mF cm-3 (volume of whole device) at 6.5 mA cm-3 . The performance of the hybrid electrode with redox-active potassium iodide at the graphene surface was tested...
May 22, 2018: ChemSusChem
Minjun Yang, Richard G Compton
The redox chemistry of solid α-HgS particles is revealed using a carbon/PVDF composite containing α-HgS, carbon black, polyvinylidene fluoride (PVDF). The electrochemical behaviour of the carbon/PVDF composite is first characterised with three water insoluble organic solids. Then the reduction of solid α-HgS particles is investigated and found to occur at a high negative potential, -1.82V vs saturated mercury sulphate reference electrode, to form metallic mercury and sulphide ions. The subsequent oxidation of metallic mercury and sulphide occurs at +0...
May 22, 2018: Chemistry: a European Journal
Seongrok Seo, Seonghwa Jeong, Changdeuck Bae, Nam-Gyu Park, Hyunjung Shin
Despite the high power conversion efficiency (PCE) of perovskite solar cells (PSCs), poor long-term stability is one of the main obstacles preventing their commercialization. Several approaches to enhance the stability of PSCs have been proposed. However, an accelerating stability test of PSCs at high temperature under the operating conditions in ambient air remains still to be demonstrated. Herein, interface-engineered stable PSCs with inorganic charge-transport layers are shown. The highly conductive Al-doped ZnO films act as efficient electron-transporting layers as well as dense passivation layers...
May 22, 2018: Advanced Materials
Jing Du, Zehua Zou, Ailing Yu, Cailing Xu
Exploiting highly active oxygen evolution reaction electrocatalysts is of great importance in the cost-effective generation of clean fuels. Herein, the preparation of NiMn-layered double hydroxide with selenization is adopted to reduce the charge transfer resistance of the electrocatalytic oxygen evolution reaction and enhance electrocatalytic performance. As a result, this selenization product of NiMn-layered double hydroxide can reach a current density of 10 mA cm-2 at a low overpotential of 280 mV on glassy carbon electrode in 1...
May 22, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Haiwen Gao, Xiaohong Wang, Ganghu Wang, Chen Hao, Saisai Zhou, Chengxiang Huang
In recent years, the electrochemical properties of supercapacitors have been greatly improved due to continuous improvement in their composite materials. In this study, an urchin-like MgCo2O4@PPy/NF (MgCo2O4@polypyrrole/Ni foam) core-shell structure composite material was successfully developed as an electrode for supercapacitors. The MCP-2 composite material, obtained by a hydrothermal method and in situ chemical oxidative polymerization, shows a high specific capacitance of 1079.6 F g-1 at a current density of 1 A g-1, which is much higher than that of MC (783...
May 22, 2018: Nanoscale
Youngin Goh, Sanghun Jeon
Ferroelectric tunnel junctions (FTJs) have attracted research interest as promising candidates for non-destructive readout non-volatile memories. Unlike conventional perovskite FTJs, hafnia FTJ offers many advantages in terms of scalability and CMOS compatibility. However, so far, hafnia FTJ has shown poor endurance and relatively low resistance ratio and these have remained the issue for real device applications. In our study, we fabricated HfZrO-based FTJ with various electrodes (TiN, Si, SiGe, Ge) and improved the memory performance of HfZrO-based FTJ by using the asymmetry of the charge screening lengths of the electrodes...
May 22, 2018: Nanotechnology
Kyoung-Ryul Lee, Sung Hwan Jang, Inhwa Jung
We investigated the acoustic performance of electrostatic sound-generating devices consisting of bilayer graphene on polyimide (PI) film. Total sound pressure level (SPL) of sound generated from the devices was measured as a function of source frequency by sweeping, and frequency spectra were measured at 1/3 octave band frequencies. The relationship between various operation conditions and total SPL was determined. In addition, the effects of changing voltage level, adding a DC offset, and using two pairs of electrodes were evaluated...
May 22, 2018: Nanotechnology
Young-Kyun Lim, Choong-Hyun Lee, Eung-Seok Lee, Dae-Soon Lim
In the study, a hollow boron-doped diamond (BDD) nanostructure electrode is fabricated to increase the reactive surface area for electrochemical applications. Tungsten oxide nanorods are deposited on the silicon substrate as a template by the hot filament chemical vapor deposition (HFCVD) method. The template is coated with a 100 nm BDD layer deposited by HFCVD to form a core-shell nanostructure. The WOx core is finally electrochemically dissolved to form hollow BDD nanostructure. The fabricated hollow BDD nanostructure electrode is investigated via scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy...
May 22, 2018: Nanotechnology
Lin Zhu, Bowen Li, Kailun Yao
Thermoelectric transport properties of Ti doped or adsorbed monolayer blue phosphorene are investigated by density functional theory calculations combined with the nonequilibrium Green's function formalism. The thermal giant magnetoresistance and a nearly 100% spin polarization which solely relies on the temperature gradient of electrodes without bias or gate voltage are observed. Moreover, the spin Seebeck effect is also found. Furthermore, taking into account the electronic and phonon dispersion, the thermoelectric merit for Ti doping in the monolayer blue phosphorene at room temperature is also studied, the maximum value of thermoelectric merit can reach 1...
May 22, 2018: Nanotechnology
Zhijiang Wang, Lina Wu, Kun Sun, Ting Chen, Zhaohua Jiang, Tao Cheng, William A Goddard
We have explored functionalizing metal catalysts with surface ligands as an approach to facilitate electrochemical carbon dioxide reduction reaction (CO2 RR). To provide a molecular level understanding of the mechanism by which this enhancement occurs, we combine in situ spectroscopy analysis with an interpretation based on quantum mechanics (QM) calculations. We find that a surface ligand can play a critical role in stabilizing the chemisorbed CO2 , which facilitates CO2 activation and leads to a 0.3 V decrease in the overpotential for carbon monoxide (CO) formation...
May 23, 2018: Journal of Physical Chemistry Letters
Pengju Li, Yang Gui, Daniel John Blackwood
Toxic metal ions, such as Ni2+ and Mn2+, in industrial waste streams are non-biodegradable and can cause damage to the human body. Electrochemical cleaning techniques are attractive as they offer more control and produce less sludge than chemical / biological approaches without the high pressures needed for membranes. Here nanoneedle structured α-MnO2/carbon fiber paper (CFP) composites were synthesized by a hydrothermal approach and used as electrodes for combined electro-adsorption and capacitive deionization removal of nickel and manganese ions from pseudo industrial waste streams...
May 22, 2018: ACS Applied Materials & Interfaces
Meng Zhang, Qingyu Zhai, Liping Wan, Li Chen, Yu Peng, Chunyan Deng, Juan Xiang, Jiawei Yan
Layer-by-layer dissolution and permeable pore formation are two typical membrane damage pathways, which induce membrane function disorder and result in serious disease, such as Alzheimer's disease, Keshan disease, Sickle-cell disease and so on. To effectively distinguish and sensitively monitor these two typical membrane damage pathways, a facile electrochemical impedance strategy was developed on a porous self-assembly monolayer (pSAM) supported bilayer lipid membrane (BLM). The pSAM was prepared by selectively electrochemical reductive desorption of the mercaptopropionic acid in a mixed mercaptopropionic acid/11-mercaptoundecanoic acid self-assembled monolayer, which created plenty of nanopores with tens of nanometers in diameter and several nanometers in height (defined as inner-pores)...
May 22, 2018: Analytical Chemistry
Şener Sağlam, Ayşem Üzer, Erol Erçağ, Reşat Apak
Since nitroaromatic and nitramine type energetic materials, mostly arising from military activities, are persistent pollutants in soil and groundwater, on-site sensing of these hazardous chemicals has gained importance. A novel electrochemical sensor was designed for detecting nitroaromatic and nitramine type energetic materials, relying on gold nanoparticles (Aunano ) -modified glassy carbon (GC) electrode coated with nitro-energetic memory poly(carbazole-aniline) copolymer (Cz- co-ANI) film (e.g., TNT memory-GC/P(Cz- co-ANI)-Aunano modified electrode)...
May 22, 2018: Analytical Chemistry
Rupali Deshmukh, Micha Calvo, Murielle Schreck, Elena Tervoort, Alla S Sologubenko, Markus Niederberger
We report a solution-phase approach to the synthesis of crystalline copper nanowires (Cu NWs) with aspect ratio > 1000 via a new catalytic mechanism comprising copper ions. The synthesis involves the reaction between copper(II) chloride and copper(II) acetylacetonate in a mixture of oleylamine and octadecene. Reaction parameters such as the molar ratio of precursors as well as the volume ratio of solvents offer the possibility to tune the morphology of the final product. A simple low-cost spray deposition method was used to fabricate Cu NW films on a glass substrate...
May 22, 2018: ACS Applied Materials & Interfaces
Jianxiong Zhu, Yali Zhu, Weixing Song, Hui Wang, Min Gao, Minkyu Cho, Inkyu Park
This paper reports zinc oxide (ZnO) coated piezoelectret polypropylene (PP) microfibers with a structure of two opposite arc-shaped braces for enhanced mechanical energy harvesting. The ZnO film was coated onto PP microfibers via magnetron sputtering to form a ZnO/PP compound structure. Triboelectric Nanogenerator (TENG) based on ZnO/PP microfiber compound film was carefully designed with two opposite arc-shaped braces. The results of this study demonstrated that the mechanical energy collection efficiency of TENG based on piezoelectret PP microfiber was greatly enhanced by the coated ZnO and high voltage corona charging method...
May 22, 2018: ACS Applied Materials & Interfaces
Bonita R Lam, Annette R Rowe, Kenneth H Nealson
Extracellular electron transport (EET) is a microbial process that allows microorganisms to transport electrons to and from insoluble substrates outside of the cell. Although progress has been made in understanding how microbes transfer electrons to insoluble substrates, the process of receiving electrons has largely remained unexplored. We investigated redox potentials favorable for donating electrons to dissolved and insoluble components in Catalina Harbor marine sediment by combining electrochemical techniques with geochemistry and molecular methods...
May 22, 2018: Environmental Microbiology
Hanyang Zhang, Zhifei Li, Wei Xu, Yicong Chen, Xiulei Ji, Michael M Lerner
There has been a major effort recently to develop new rechargeable sodium-ion electrodes. In lithium ion batteries, LiC6 forms from graphite and de-solvated Li cations during the first charge. With sodium ions, graphite only shows a significant capacity when Na+ intercalates as a solvated complex, resulting in ternary graphite intercalation compounds (GICs). Although this chemistry has been shown to be highly reversible and to support high rates in small test cells, these GICs can require &gt;250% volume expansion and contraction during cycling...
May 22, 2018: Nanotechnology
Yanmei Yang, Qiaoshi Zhao, Yang Liu, Xiaona Liu, Yanru Chu, Huazhu Yan, Yumei Fan, Simeng Huo, Limei Wang, Qun Lou, Ning Guo, Dianjun Sun, Yanhui Gao
Skeletal fluorosis is a metabolic bone and joint disease caused by excessive accumulation of fluoride in the bones. Compared with Kazakhs, Tibetans are more likely to develop moderate and severe brick tea type skeletal fluorosis, although they have similar fluoride exposure. Single nucleotide polymorphisms (SNPs) in frizzled-related protein (FRZB) have been associated with osteoarthritis, but their association with the risk of skeletal fluorosis has not been reported. In this paper, we investigated the association of three SNPs (rs7775, rs2242070 and rs9288087) in FRZB1with brick tea type skeletal fluorosis risk in a cross-sectional case-control study conducted in Sinkiang and Qinghai, China...
May 21, 2018: Archives of Toxicology
Moteb M Alqahtani, Atif M Ali, Farid A Harraz, M Faisal, Adel A Ismail, Mahmoud A Sayed, M S Al-Assiri
Mesoporous α-Fe2 O3 has been synthesized via a simple sol-gel procedure in the presence of Pluronic (F-127) triblock copolymer as structure directing agent. Silver (Ag) nanoparticles were deposited onto α-Fe2 O3 matrix by the photochemical reduction approach. Morphological analysis revealed the formation of Ag nanoparticles with small sizes < 20 nm onto the mesoporous structure of α-Fe2 O3 possessing < 50 nm semi-spherical shape. The XRD, FTIR, Raman, UV-vis, PL, and N2 sorption isotherm studies confirmed the high crystallinity, mesoporosity, and optical characteristics of the synthesized product...
May 21, 2018: Nanoscale Research Letters
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"