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https://www.readbyqxmd.com/read/28335500/comparison-of-two-types-of-overoxidized-pedot-films-and-their-application-in-sensor-fabrication
#1
Yun Hui, Chao Bian, Jinfen Wang, Jianhua Tong, Shanhong Xia
Poly(3,4-ethylenedioxythiophene) (PEDOT) films were prepared by electro-oxidation on Au microelectrodes in an aqueous solution. Electrolyte solutions and polymerization parameters were optimized prior to overoxidation. The effect of overoxidation time has been optimized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), which results in the film overoxidized for 45 s at 1.35 V presenting a strong adsorption. The other one-step overoxidation film prepared by direct CV ranging from -0...
March 19, 2017: Sensors
https://www.readbyqxmd.com/read/28335366/nano-copper-oxide-modified-carbon-cloth-as-cathode-for-a-two-chamber-microbial-fuel-cell
#2
Feng Dong, Peng Zhang, Kexun Li, Xianhua Liu, Pingping Zhang
In this work, Cu₂O nanoparticles were deposited on a carbon cloth cathode using a facile electrochemical method. The morphology of the modified cathode, which was characterized by scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) tests, showed that the porosity and specific surface area of the cathode improved with longer deposition times. X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV) results showed that cupric oxide and cuprous oxide coexisted on the carbon cloth, which improved the electrochemical activity of cathode...
December 9, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28335348/electrochemical-synthesis-of-polypyrrole-reduced-graphene-oxide-and-gold-nanoparticles-composite-and-its-application-to-hydrogen-peroxide-biosensor
#3
Baoyan Wu, Na Zhao, Shihua Hou, Cong Zhang
Here we report a facile eco-friendly one-step electrochemical approach for the fabrication of a polypyrrole (PPy), reduced graphene oxide (RGO), and gold nanoparticles (nanoAu) biocomposite on a glassy carbon electrode (GCE). The electrochemical behaviors of PPy-RGO-nanoAu and its application to electrochemical detection of hydrogen peroxide were investigated by cyclic voltammetry. Graphene oxide and pyrrole monomer were first mixed and casted on the surface of a cleaned GCE. After an electrochemical processing consisting of the electrooxidation of pyrrole monomer and simultaneous electroreduction of graphene oxide and auric ions (Au(3+)) in aqueous solution, a PPy-RGO-nanoAu biocomposite was synthesized on GCE...
November 21, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28335339/electrochemical-and-capacitive-properties-of-carbon-dots-reduced-graphene-oxide-supercapacitors
#4
Yong-Qiang Dang, Shao-Zhao Ren, Guoyang Liu, Jiangtao Cai, Yating Zhang, Jieshan Qiu
There is much recent interest in graphene-based composite electrode materials because of their excellent mechanical strengths, high electron mobilities, and large specific surface areas. These materials are good candidates for applications in supercapacitors. In this work, a new graphene-based electrode material for supercapacitors was fabricated by anchoring carbon dots (CDs) on reduced graphene oxide (rGO). The capacitive properties of electrodes in aqueous electrolytes were systematically studied by galvanostatic charge-discharge measurements, cyclic voltammetry, and electrochemical impedance spectroscopy...
November 14, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28335305/simultaneous-detection-of-dopamine-and-uric-acid-using-a-poly-l-lysine-graphene-oxide-modified-electrode
#5
Yuehua Zhang, Wu Lei, Yujuan Xu, Xifeng Xia, Qingli Hao
A novel, simple and selective electrochemical method was investigated for the simultaneous detection of dopamine (DA) and uric acid (UA) on a poly(l-lysine)/graphene oxide (GO) modified glassy carbon electrode (PLL/GO/GCE) by differential pulse voltammetry (DPV). The electrochemically prepared PLL/GO sensory platform toward the oxidation of UA and DA exhibited several advantages, including high effective surface area, more active sites and enhanced electrochemical activity. Compared to the PLL-modified GCE (PLL/GCE), GO-modified GCE and bare GCE, the PLL/GO/GCE exhibited an increase in the anodic potential difference and a remarkable enhancement in the current responses for both UA and DA...
September 28, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28334659/nickel-selenide-reduced-graphene-oxide-nanocomposite-as-counter-electrode-for-high-efficient-dye-sensitized-solar-cells
#6
Jia Dong, Jihuai Wu, Jinbiao Jia, Leqing Fan, Jianming Lin
Nickel selenide/reduced graphene oxide (Ni0.85Se/rGO) nanosheet composite is synthesized by a facile hydrothermal process and used as counter electrode (CE) for dye-sensitized solar cells (DSSC). The Ni0.85Se/rGO film spin-coated on FTO show prominent electrocatalytic activity toward I3(-)/I(-). The electrocatalytic ability of Ni0.85Se/rGO film is verified by photocurrent-voltage curves, cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization curves. On account of its decent electrical conductivity and superior electrocatalytic activity, the DSSC using optimal Ni0...
March 6, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28332677/tuneable-reversible-redox-of-cobalt-iii-carbazole-complexes
#7
Michael S Bennington, Humphrey L C Feltham, Zoë J Buxton, Nicholas G White, Sally Brooker
Four tridentate carbazole-based ligands, HL((t)Bu/H) {3,6-di(tert-butyl)-1,8-bis[5-(3-benzyl-1,2,3-triazole)]-9H-carbazole}, HL((t)Bu/(t)Bu) {3,6-di(tert-butyl)-1,8-bis[5-(3-(4-tert-butyl)benzyl-1,2,3-triazole)]-9H-carbazole}, HL(H/H) {1,8-bis[5-(3-benzyl-1,2,3-triazole)]-9H-carbazole} and HL(H/(t)Bu) {1,8-bis[5-(3-(4-tert-butyl)benzyl-1,2,3-triazole)]-9H-carbazole}, were prepared and complexed with cobalt(ii) tetrafluoroborate. In situ air oxidation resulted in cobalt(iii) complexes 1-4 with the general formula [Co(III)(L)2]BF4·xH2O (1: L = L((t)Bu/H), x = 2; 2: L = L((t)Bu/(t)Bu), x = 1; 3: L = L(H/H), x = 0...
March 23, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28332478/addressed-immobilization-of-biofunctionalized-diatoms-on-electrodes-by-gold-electrodeposition
#8
S Leonardo, D Garibo, M Fernández-Tejedor, C K O'Sullivan, M Campàs
Diatoms are single cell microalgae with a silica shell (frustule), which possess a micro/nanoporous pattern of unparalleled diversity far beyond the possibilities of current micro- and nanofabrication techniques. To explore diatoms as natural three-dimensional nanostructured supports in sensing and biosensing devices, a simple, rapid and stable method to immobilize diatoms via gold electrodeposition is described. In this process, gold microstructures are formed, immobilizing diatoms by entrapment or crossing their nanopores...
March 23, 2017: Biofabrication
https://www.readbyqxmd.com/read/28328195/degradation-dynamics-for-electrochromic-wo3-films-under-extended-charge-insertion-extraction-unveiling-physicochemical-mechanisms
#9
Rui-Tao Wen, Sara Malmgren, Claes G Granqvist, Gunnar A Niklasson
Degradation of electrochromic thin films under extended charge insertion/extraction is a technically important phenomenon for which no in-depth understanding is currently at hand. Here we report on an explorative study of sputter-deposited WO3 films in a Li-ion-conducting electrolyte by use of cyclic voltammetry, in situ optical transmittance, and impedance spectroscopy. A cycling-dependent decrease of the charge capacity could be accurately modeled by a power-law function, and impedance spectroscopy gave evidence for anomalous diffusion as well a higher charge transfer resistance during deintercalation than during intercalation...
March 22, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28325305/rapid-synthesis-of-ethyl-cellulose-supported-platinum-nanoparticles-for-the-non-enzymatic-determination-of-h2o2
#10
Raj Karthik, Natarajan Karikalan, Shen-Ming Chen
Cellulose derivatives are one of the carbohydrate polymers which received a great interest in the construction of nanostructured materials. Particularly, the ethyl cellulose provides an enormous support to the metal nanoparticles. To the best of our knowledge, this is the first time report for the simple and rapid synthesis of ethyl cellulose (EC) supported platinum nanoparticles (PtNPs) for the determination of non-enzymatic hydrogen peroxide (H2O2). The PtNPs/EC composite was confirmed by various characterizations such as fourier transform infra-red spectra, energy dispersive X-ray spectra, field emission scanning electron microscope and cyclic voltammetry...
May 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28322401/comparisons-of-mn2s2vs-bipyridine-as-redox-active-ligands-to-manganese-and-rhenium-in-l-l-m-co-3cl-complexes
#11
Allen M Lunsford, Kristina F Goldstein, Matthew A Cohan, Jason A Denny, Nattamai Bhuvanesh, Shengda Ding, Michael B Hall, Marcetta Y Darensbourg
The bipyridine ligand is renowned as a photo- and redox-active ligand in catalysis; the latter has been particularly explored in the complex Re(bipy)(CO)3Cl for CO2 reduction. We ask whether a bidentate, redox-active MN2S2 metallodithiolate ligand in heterobimetallic complexes of Mn and Re might similarly serve as a receptor and conduit of electrons. In order to assess the electrochemical features of such designed bimetallics, a series of complexes featuring redox active MN2S2 metallodithiolates, with M = Ni(2+), {Fe(NO)}(2+), and {Co(NO)}(2+), bound to M'(CO)3X, where M' = Mn and Re, were synthesized and characterized using IR and EPR spectroscopies, X-ray diffraction, cyclic voltammetry, and density functional theory (DFT) computations...
March 21, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28322349/an-aqueous-electrolyte-of-the-widest-potential-window-and-its-superior-capability-for-capacitors
#12
Hiroshi Tomiyasu, Hirokazu Shikata, Koichiro Takao, Noriko Asanuma, Seiichi Taruta, Yoon-Yul Park
A saturated aqueous solution of sodium perchlorate (SSPAS) was found to be electrochemically superior, because the potential window is remarkably wide to be approximately 3.2 V in terms of a cyclic voltammetry. Such a wide potential window has never been reported in any aqueous solutions, and this finding would be of historical significance for aqueous electrolyte to overcome its weak point that the potential window is narrow. In proof of this fact, the capability of SSPAS was examined for the electrolyte of capacitors...
March 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28321442/improved-electron-hole-separation-and-migration-in-anatase-tio2-nanorod-reduced-graphene-oxide-composites-and-their-influence-on-photocatalytic-performance
#13
Gregor Žerjav, Muhammad Shahid Arshad, Petar Djinović, Ita Junkar, Janez Kovač, Janez Zavašnik, Albin Pintar
The as-synthesized TiO2 nanorods a-TNR (amorphous TiO2 layer covering the crystalline anatase TiO2 core) and TNR (fully crystalline anatase TiO2) were decorated with reduced graphene oxide (rGO) to synthesize two series of TiO2 + rGO composites with different nominal loadings of GO (from 4 to 20 wt%). The structural, surface and electronic properties of the obtained TiO2 + rGO composites were analyzed and correlated to their performance in the photocatalytic oxidation of aqueous bisphenol A solution. X-ray photoelectron spectroscopy (XPS) analyses revealed that charge separation in TiO2 + rGO composites is improved due to the perfect matching of TiO2 and rGO valence band maxima (VBM)...
March 21, 2017: Nanoscale
https://www.readbyqxmd.com/read/28319904/sensitivity-enhancement-of-graphene-zinc-oxide-nanocomposite-based-electrochemical-impedance-genosensor-for-single-stranded-rna-detection
#14
Sze Shin Low, Hwei-San Loh, Jian Sheng Boey, Poi Sim Khiew, Wee Siong Chiu, Michelle T T Tan
An efficient electrochemical impedance genosensing platform has been constructed based on graphene/zinc oxide nanocomposite produced via a facile and green approach. Highly pristine graphene was synthesised from graphite through liquid phase sonication and then mixed with zinc acetate hexahydrate for the synthesis of graphene/zinc oxide nanocomposite by solvothermal growth. The as-synthesised graphene/zinc oxide nanocomposite was characterised with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and X-ray diffractometry (XRD) to evaluate its morphology, crystallinity, composition and purity...
February 27, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28319868/synthesis-characterization-of-amide-substituted-dexibuprofen-derivatives-and-their-spectral-voltammetric-and-docking-investigations-for-dna-binding-interactions
#15
Nasima Arshad, Muhammad Zafran, Zaman Ashraf, Fouzia Perveen
Three amide derivatives - methyl-2-[2-(4-isobutylphenyl)propanamido]propanoate (Dex-2), methyl 2-[2-(4-isobutylphenyl) propanamido]-3-phenylpropanoate (Dex-3) and methyl 2-[2-(4-isobutylphenyl)-propanamido]-4-methylpentanoate (Dex-4) of dexibuprofen (Dex-1) 2-(4-isobutylphenyl)propanoic acid were synthesized and conformed for structures by physical data and spectral analysis. Further, all the compounds were studied for their binding with ds.DNA through experimental (UV-visible/and fluorescence spectroscopy, cyclic voltammetry) and theoretical (molecular docking) techniques...
March 3, 2017: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/28319034/sc-co-sub-2-sub-assisted-process-for-high-energy-density-aerogel-supercapacitor-the-effect-of-go-loading
#16
Maria Sarno, Lucia Baldino, Carmela Scudieri, Stefano Cardea, Paolo Ciambelli, Ernesto Reverchon
Energy density, safety, simple and environmentally friendly preparation methods are very significant aspects in the realization of a compact supercapacitor. Herein we report the use of a supercritical CO2 assisted gel drying process (SC-CO2) for the preparation of porous electrodes containing dispersed graphene in a Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) binder membrane to sandwich in a new portable supercapacitor based on graphene oxide (GO). A GO loading of 60 wt.% has been found to give the better combination of factors (porosity, wettability, mechanical and electrochemical properties,...
March 20, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28318236/in-situ-monitoring-potential-dependent-electrochemical-process-by-liquid-nuclear-magnetic-resonance-nmr-spectroelectrochemical-determination-a-proof-of-concept-study
#17
Shuo-Hui Cao, Zu-Rong Ni, Long Huang, Hui-Jun Sun, Biao Tang, Liangjie Lin, Yuqing Huang, Zhi-You Zhou, Shi-Gang Sun, Zhong Chen
We report the design and the performance of a two-chamber thin-layer electrochemical device for in situ potential-dependent liquid nuclear magnetic resonance (NMR) measurement. Liquid NMR spectra, simultaneously recorded with cyclic voltammetry (CV), have been obtained to reveal molecular changes with potentials scanning. As a proof of concept, redox properties of 1,4-benzoquinone based systems have been investigated, and a π dimerization has been identified by combining both in situ and ex situ NMR analyses...
March 20, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28317963/comparison-of-fast-electron-transfer-kinetics-at-platinum-gold-glassy-carbon-and-diamond-electrodes-using-fourier-transformed-ac-voltammetry-and-scanning-electrochemical-microscopy
#18
Sze-Yin Tan, Robert A Lazenby, Kiran Bano, Jie Zhang, Alan M Bond, Julie V Macpherson, Patrick R Unwin
Heterogeneous electron transfer (ET) processes at electrode/electrolyte interfaces are of fundamental and applied importance and are extensively studied by a range of electrochemical techniques, all of which have various attributes but also limitations. The present study focuses on the one-electron oxidation of tetrathiafulvalene (TTF) and reduction of tetracyanoquinodimethane (TCNQ) in acetonitrile solution by two powerful electrochemical techniques: Fourier-transformed large amplitude alternating current voltammetry (FTACV); and scanning electrochemical microscopy (SECM), both of which are supported by detailed theoretical models...
March 20, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28317708/sensitive-determination-of-capsaicin-in-pepper-samples-using-a-voltammetric-platform-based-on-carbon-nanotubes-and-ruthenium-nanoparticles
#19
Aysegul Kutluay Baytak, Mehmet Aslanoglu
A voltammetric platform based on modifying glassy carbon electrodes (GCEs) with ruthenium nanoparticles decorated carbon nanotubes (CNTs) was applied for the determination of capsaicin in pepper samples. The nanoparticles of ruthenium (RuNPs) were obtained at carbon nanotubes modified GCE by cyclic voltammetry. The composite of RuNPs-CNTs was characterized by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The proposed voltammetric platform, RuNPs/CNTs/GCE, highly improved the voltammetric process of capsaicin in comparison to the CNTs/GCE and bare GCE...
August 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28316627/green-synthesis-and-characterization-of-silver-nanoparticles-using-citrullus-lanatus-fruit-rind-extract
#20
Michael Ndikau, Naumih M Noah, Dickson M Andala, Eric Masika
The wide-scale application of silver nanoparticles (AgNPs) in areas such as chemical sensing, nanomedicine, and electronics has led to their increased demand. Current methods of AgNPs synthesis involve the use of hazardous reagents and toxic solvents. There is a need for the development of new methods of synthesizing AgNPs that use environmentally safe reagents and solvents. This work reports a green method where silver nanoparticles (AgNPs) were synthesized using silver nitrate and the aqueous extract of Citrullus lanatus fruit rind as the reductant and the capping agent...
2017: International Journal of Analytical Chemistry
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