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2015 Fall

Nanomaterials,Nanostructures and Nano devices

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Nanocarbon Electrochemistry and Interface

This symposium will focus on electrochemical characterization and properties of diamond, CNTs, graphene, carbon particles and nanocomposites, etc. The key topics will include their application in electroanalysis, biosensing, electrocatalyst, electrosynthesis, environmental degredation, energy conversion and storage, etc.

 

Scope

 

This symposium will focus on the electrochemistry and interfaces based on nanocarbons, including novel carbon films (e.g. conductive diamond, fullerenes, DLC, CNTs, graphene, etc.), carbon nanoparticles (e.g. diamond nanoparticles, carbon dots, carbon powders, graphene dots, etc.) and micro-fabricated and CVD grown carbon structures (e.g. carbon foam, diamond nanowires, porous diamond, carbon nanofibers, etc.) as well as carbon nanocomposites (e.g. diamond/SiC nanocomposite films, carbon nitrite, etc.). Electrochemical characterization of these nanocarbon materials in different media (including aqueous and non-aqueous solutions (organic and ionic liquids) and their interfacial properties will be covered. Of particular focus will be the relationships between the carbon bulk structure, electronic properties and surface chemistry their electrochemical performance (e.g. potential window, capacitance, redox activity, electrode kinetics and interactions, etc.). Applications of the nanocarbon materials in electroanalysis, electrocatalyst, electrosynthesis, environmental degradation, and energy storage and conversion will be covered. In vivo and in vitro electrochemical sensing, electrocatalytic reactions (e.g. catalyst support, metal-free catalytic reactions), organic synthesis using nanocarbon electrodes, electrochemical-photochemical degradation of environmental pollutants, supercapacitors and batteries from carbon nanomaterials are currently key topics in the field. The symposium will also include contributions on the fabrication, characterization, and application of micro and nanostructured carbon materials (e.g. micro-, ultramicro-, nano- electrode arrays, tips, etc.) and their characterization by scanning electrochemical microscopy, electrochemical AFM and spectroelectrochemistry.

 

Hot topics to be covered by the symposium

 

  • Electrochemical properties of nanocarbons and related nanocomposites
  • Simulation of carbon nanoelectrochemistry
  • Synthesis of nanocarbons for electrochemistry
  • Nanocarbon electrochemical and biochemical sensing
  • Electrosynthesis using nanocarbon electrodes
  • Electrocatalysts on nanocarbon electrodes
  • Nanocarbon electrodes for enviromental degredation
  • Nanocarbon electrodes for electrochemical energy conversion and storage
  • Electrochemistry at carbon nanostructures
  • Electrochemical functionalization of nanocarbons and their applications
  • Fabrication and applications of nanocarbon electrochemical devices

 

Tentative list of invited speakers

 

  • R. L. McCreery, University of Alberta, Canada Advanced Carbon Materials for Molecular Electrochemistry
  • K. P. Loh, National University of Singapore, Singapore Metal-Free Catalysts from Nanocarbons
  • C.E. Nebel, Fraunhofer Institute for Applied Solid State Physics (IAF), Germany Future of Diamond Electrochemistry
  • S. R. Waldvogel, University of Gutenberg-Universitat Mainz, Germany Electrochemical Organic Synthesis Using Carbon Electrodes
  • E. Brillas, Universitat de Barcelona, Spain Waste Water Treatment by Boron-Doped Diamond Electrodes
  • M. Panizza, Univeisita di Genova, Italy Degradation of Environmental Toxic Materials Using Carbon Electrodes
  • C.A. Martinez-Huitle, Campus Universitario-Lagoa Nova, Brasil Carbon Materials for Energy Storage and Conversion
  • M. Opallo, Institute of Physical Chemistry, Warsaw, Poland Electrochemistry of Nanocarbons in Ionic Liquids
  • B. A. Patel, University of Brighton, UK Bioanalytical Application of Boron Doped Diamond Electrodes
  • R. Zhou, IBM Reseach Center, USA Simulation and Experiments of Carbon Biointerface
  • Z. Liu, Soochow University, China Nanocarbons for Drug Delivery, Bioimaging and Related Applications
  • J. Li, Tsinghua University, China Energy Storage Using Nanocarbons

 

Tentative list of scientific committee members

 

 

  • J. Wang, University California San Diego (UCSD), USA
  • R. G. Compton, University of Oxford, Oxford, UK
  • H. Dai, Stanford University, USA
  • J.A. Garrido, Walter Schottky Institute, TUM, Germany
  • H. Kawarada, Waseda University, Japan
  • P. Mailley, Université Joseph Fourier, France
  • M.S. Strano, MIT, USA
  • S.T. Lee, Soochow University, China
  • F. Treussart, ENS Cachan, France
  • D.-W. Pang, Wuhan University, China

 

Start atSubject View AllNum.
 
Carbon for Energy : Richard McCreey
11:00
Authors : Christoph E. Nebel, Wolfgang Müller-Sebert, Georgia Lewes-Malandrakis, Fang Gao
Affiliations : Fraunhofer-Institute for Applied Solid State Physics IAF, Tullastr. 72, Freiburg, Germany

Resume : Batteries are increasingly important for a variety of applications which are mobile and disconnected from power grids. Energy and power demands of devices define the design and concept of the storage devices. While lithium ion batteries have aided the portable electronics during the past two decades due to their high energy storage capability, they are too slow for devices which need energy burst. Here dielectric capacitors are the one to provide energy when peak power is required, but they are limited with respect to energy delivery. Between these two extremes supercapacitors (SCs), also called ultracapacitors or electrochemical capacitors will fill the gap in the future. They need to combine relative fast charging/de-charging cycles with respect to optimized energy supply. This is the field of surface enlarge capacitors, which show textured surfaces, lattice expanded structures or surfaces composed out of long and dense wire structures. Besides surface enlargements, the electrochemical potential window affects equally important the energy and power properties of supercaps. It is well known that diamond shows the wides electrochemical potential window of all known electrode materials. Diamond is also chemical stable and can meanwhile be deposited on large areas in nano- or poly-crystalline structures. By adding boron to the diamond lattice, diamond becomes very conductive (p-type) and is used as electrochemical electrode in a variety of applications. In this presentation we will introduce the realization of supercaps from diamond Si-based surfeces with textures. These layers are overgrown with heavily boron-doped nano-crystalline diamond films. For these experiments we used silicon-nano-wires (Si-NWs) grown by a VLS-process as substrates for the overgrowth with conducting diamond coatings. The SiNWs had typical dimensions of 10 µm length at diameters of 150 nm. Prior to overgrowth we applied a special seeding procedure using a colloidal suspension of diamond nanoparticles in water. This technique gives rise to nucleation densities in the range of 1011 cm-2. Diamond deposition was carried out in our multi-antenna plasma enhanced CVD-reactors. The standard 6 kW system with 2.45 GHz is capable of coating substrates up to 3 inch in diameter, wereas in the upscaled 915 MHz system 6 inch substrates can be coated. As boron source we used trimethyboron (TMB); the doping level was up to 5x1020 cm-3. We realized uniform diamond coatings with a thickness in the range of 200 nm. Even densely packed Si-NWs with high aspect ratio could be readily coated. Alternatively, we prepared electrodes with all-diamond nanowires by ICP etching of 10 µm thick boron-doped polycrystalline CVD diamond with Ti- or Ni nanoparticles as etching mask. The all-diamond nanowires have a much lower aspect ratio compared to overgrown Si-NWs; however the surface enhancement is up to 25 times as compared to unstructured polycrystalline films. We will summarize related physical and electrochemical properties to compare the device with standard supercaps and to discuss future applications of this new device.

R.2.1
 
Carbon Interface : Hyacinthe Randriamahazaka
16:00
Authors : Yao Ma, Xiao Sun, Nianjun Yang,* Junhai Xia, Lei Zhang, Xin Jiang*
Affiliations : Institute of Materials Engineering, University of Siegen, 57076 Siegen, Germany

Resume : Carbon nanostructures are difficult to be synthesized with precisely controlled shapes. A facet-selective-catalytic process was thus proposed to prepare polymer-liked carbon nanostructures with different shapes, covering straight carbon nanofiber, carbon nano Y-junction, carbon nano-hexapus, and carbon nano-octopus. A thermal chemical vapour deposition process was applied to synthesize these multi-branched carbon nanostructures at temperatures lower than 350 oC. Cu nanoparticles were utilized as the catalyst and acetylene as the reaction gas. The growth of those multi-branched nanostructures was realized via the selective growth of polymer-like sheets on certain indexed facets of Cu catalyst. The Vapor-Facet-Solid (VFS) mechanism, a new growth mode, has been proposed to interpret such a growth in the steps of formation, diffusion and coupling of carbon contained oligomers, as well as their final precipitation to form nanostructures on the selective Cu facets.

R.4.1
16:30
Authors : Min Wang, Chao Ruan, Yongfu Lian
Affiliations : Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education,School of Chemistry and Materials, Heilongjiang University, Harbin 150080, China

Resume : Carbon nano-onions(CNOs) were fabricated by electric arc-discharge method with nickel powder as catalyst. The morphology and structure of the obtained samples were characterized by field-emission scanning electron microscope, transmission electron microscopy, Raman spectrum and X-ray diffraction. The results of cyclic voltammograms shows that the current peak value is related to the loading of CNOs on electrode surface. With the loading of CNOs the peak current value increases. Thus, it is estimated that the CNOs could provide accessible external surface area for ion adsorption.

R.8.10
 
Poster Session : Quan Yuan, Dai-Wen Pang
17:30
Authors : Okoth Otieno Kevin, Kai Yan, Lan Liu, Jingdong Zhang
Affiliations : School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan 430074, P.R. China

Resume : A simple but sensitive electrochemical method was proposed for simultaneous determination of paracetamol (PCT) and diclofenac (DCF) based on poly(diallyldimethylammonium chloride) (PDDA) functionalized graphene (GR). Although electrochemical impedance analysis revealed that both GR and PDDA-GR modification could obviously facilitate the electron transfer on glassy carbon electrode (GCE), the electrochemical responses of PCT and DCF mixture on two modified electrodes were different. On GR modified electrode, the currents were enhanced while the oxidation peak difference between PCT and DCF was reduced, which led to a difficulty in the simultaneous determination of two drugs. By contrast, PDDA-GR greatly increased the electrochemical currents of both analytes while provided well-separated peak potentials. Thus, the simultaneous determination of PCT and DCF by differential pulse voltammetry was investigated on PDDA-GR. The applicability of the proposed method was verified when it was applied in determination of PCT and DCF in pharmaceuticals and lake water. Good reproducibility and high stability were also achieved.

R.R.1
17:30
Authors : Yi Liu†, Zhaohao Wang†, Qijin Wan†,*, Nianjun Yang†,‡*
Affiliations : †School of Chemistry and Chemical Engineering, Wuhan Institute of Technology, Wuhan 430073, China ‡ Institute of Materials Engineering, University of Siegen, 57076 Siegen, Germany

Resume : Graphene nano platelets (GNPs) or nano graphene platelets (NGPs) are stacks of graphene sheets with an overall thickness ranging from an average of about 5 to about 25 nm. Most of them have "platelet" morphology with a diameter of 0.5 to 25 μm. Their aspect ratios are high and can be range into the thousands. They show similar thermal and mechanical properties to CNTs but their surface areas or aspect ratios are higher. They have therefore different properstes from single or few (up to 5) layered grapheme. They have been more widely applied for various applications, such as electrochemical detections and biochemical sensing. However the properties are expected to be different from. In this presentation, we will show electrochemical deposition of gold-palladium nanoparticles (AuPd NPs) on graphene-nano-platelets (GNPs) and their application for electrocatalytic oxidation of hydrazine. The deposition was conducted using a potentiostatic mode in a mixture of HAuCl4 and H2PdCl4. This composite was characterized using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), and electrochemical impedance spectroscopy (EIS). AuPd NPs are well-dispersed on the GNP surface with particle diameter of about 30-60 nm. Moreover, they are alloyed and have porous structures. Their application was focused on the voltammetric detection of hydrazine. The chronoamperometric (CA) and cyclic voltammetric (CV) curves proved the catalytic ability of AuPd NPs towards the electrochemical oxidation of hydrazine. Under the optimized conditions, the oxidation current is linear with the concentration of hydrazine in the range of 0.02 - 166.6 μM with a sensitivity of 62.2 μA mM-1 and a detection limit of 5 nM. These results will be compared and discussed as well with those published in literature.

R.R.2
17:30
Authors : Yanying Wang, Miao Han, Kangbing Wu, Chunya Li
Affiliations : a.South–Central University for Nationalities; b. Huazhong University of Science and Technology

Resume : A novel ionic liquid, 3-{3-[(2-Aminoethyl)amino]propyl}-1-vinylimidazole bromide, was synthesized and used as a functional monomer for the fabrication of a molecularly imprinted sensing interface for myoglobin. Using the as-prepared ionic liquid as functional monomer, myoglobin from skeletal muscle as template, N,N’-Methylenebisacrylamide as crossing linker, and a redox system containing ammonium persulfate and N,N,N’,N’-Tetramethylethylenediamine as initiator, a myoglobin imprinted film was in-suit fabricated on a multiwall carbon nanotubes modified glassy carbon electrode surface at room temperature. Based on the electroactive probes, K3[Fe(CN)6]/K4[Fe(CN)6], the electrochemical sensing performances of the molecularly imprinted film electrode were investigated. The results demonstrated that the molecularly imprinted film possesses good selectivity and high sensitivity. The peak current variation is linearly related to the myoglobin concentration in the range from 6.0 10-8 to 6.0 10-6 mol L-1. The detection limit was calculated to be 9.68 10-9 mol L-1(S/N=3). Acknowledgments The authors gratefully acknowledge the financial supports from National Natural Science Foundation of China (No.21275166), China Scholarship Council (No. 201307780006), and the Natural Science Foundation of Hubei Province (No. 2015CFA092).

R.R.3
17:30
Authors : Guosong Lai, Hui Cheng, Cuiying Yin, Haili Zhang, Aimin Yu
Affiliations : Hubei Normal University

Resume : Recently, the development of nanoprobe signal amplification based ultrasensitive electrochemical immunoassay methods has shown a promising perspective in the clinical diagnosis field. Compared with the conventionally used enzymatic signal tags, gold nanoparticle (Au NP) has gained more and more attentions as a ideal nonenzymatic tags due to unique properties. In this work, we sucessfully designed a novel Au NP-functionalized graphene nanoprobe for the signal tracing of immunoassay and thus developing a new ultrasensitive electrochemcial immunoassay method. The nanoprobe was prepared through the in situ deposition of Au NPs on the surface of graphene oxide (GO) which was followed by the hydrothermal reduction to form a reduced graphene oxide (rGO)-Au NPs nanocomposite. After the antibody functionalization, the obtained rGO-Au NPs based nanoprobe was used for the signal tracing for the sandiwich immunoassay at a carbon nanotubes-modified electrode based immunosensor. The high-content Au NP tags on the quantitatively captured rGO-Au NPs nanoprobes via immunoreaction could be coveniently measurment through electrochemical stripping analysis to produce sensitive electrochemcial signal for quantitativel immunoassay. Due to the signal amplificaiton of the nanoprobe and the electron transfer acceleration of the carbon nanotubes modified on the electrode surface, ultrahigh sensitivity for the protein analyte measurement was achieved. As this gold nanoprobe is simple and cheap for preparation, and the Au NPs stripping analysis is convenient for manipulation, this nanoprobe and the developed immunoassay method provide great potentials for practical applications.

R.R.7
17:30
Authors : Su Li a, Ying Xiong b, Bing Wang b,*, Changgen Feng a,*
Affiliations : a State Key Laboratory of Explosion Science and Technology, School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China b State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010, P. R. China

Resume : Adsorptive stripping voltammetry (ASV), in the presence of suitable complex agents, is an effective approach in determining uranyl ions in the environment. Normally, poisonous mercury electrode is employed during the detection process. In this contribution, boron-doped diamond (BDD) is used as an environmental friendly alternative electrode to ASV analysis of uranyl ions. Under optimal conditions, a wide linear relationship over the concentration range from 1 ppb to 10 ppm can be obtained and a very low detection limit of about 0.012 ppb has been calculated by the standard 3 method. The low relative standard deviation for 0.5 (0.30%), 2.5 (0.98%) and 10 (0.68%) ppm uranyl ions suggests BDD electrode has good reproducibility and sensitivity. In addition, the potential interferences of several metal ions in solution are also investigated and the results confirm the possibility of uranyl ion determination in water samples containing high concentrations of metal ions.

R.R.14
17:30
Authors : Yongkang Ye1,2, Houchuan Xu1, Xuan Sun1, Xiaodong Cao1,2,*, Guoqing Liu1,2, Xiaoguang Ge3,*
Affiliations : 1. School of Biotechnology & Food Engineering, Hefei University of Technology, Hefei 230009, China 2. Wanjiang Institute of Poultry Technology, Hefei University of Technology, Xuancheng Campus, Xuancheng 242000, China 3. School of Resource & Environmental Engineering, Hefei University of Technology, Hefei 230009, China

Resume : Hydrogen sulfide (H2S), a kind of poisonous gas which can be found in forms of dissolved H2S, HS- and S2- in aqueous medium, is demonstrated to be a potential food preservation gas for prolonging postharvest shelf life of fruits [1] and vegetables [2]. It is necessary to develop fast and effective detection of these forms of H2S (classified as sulfides) that possibly remained in food in case of harm. In this work, we presented a new approach for rapid detection of sulfide using a glassy carbon electrode (GCE) modified with alizarin (Az) and reduced graphene oxide (rGO) nanosheets. The fabricate Az-rGO/GCE sensor exhibited a notable electrocatalytic activity to sulfide oxidation. Amperometric studies showed that the steady currents were related linearly to the concentrations of sulfide in the range of 0.05 to 2.25 mM. The proposed method was successfully applied in sulfide determination of hydrogen sulfide pretreated fruits, and the method was verified with recovery studies with recovery values of 91%-121%. Fig. 1. Amperometric responds to the different concentrations of sulfide on Az-rGO/GCE at applied potential of +0.225 V (vs. Ag/AgCl). Inset: TEM image of reduced graphene oxide. Reference [1] L.Y. Hu, S.L. Hu, J. Wu, Y.H. Li, et al. J. Agric. Food Chem. 2012, 60, 8684−8693 [2] S.P. Li, K.D. Hu, L.Y. Hu, et al. J. Agric. Food Chem. 2014, 62, 1119−1129

R.R.16
17:30
Authors : Siyu Yu, Yao Ma, Nianjun Yang*, Hao Zhuang, Xin Jiang*
Affiliations : Institute of Materials Engineering, University of Siegen, Paul-Bonatz-str.9-11, 57076 Siegen, Germany

Resume : Boron-doped diamond is a promising electrode and electrode support for electrochemical capacitor applications. In this presentation we will show the applications of diamond for electrical double layer capacitor and pseudosupercapacitors. The capacitance of diamond based electrical double layer capacitor only reduced 5% even after 1 000 charge-discharge cycles in 1.0 M sodium sulphate solution at a scan rate of 100 mV/s. To improve the performance of diamond based capacitors, large surface areas of diamond electrodes (for electric double layer capacitors) or diamond based composite films (for pseudosupercapacitor) are required. Carbon nanofibers on diamond electrode surface will be shown for electric double layer capacitor application as well as manganese dioxide coated diamond electrode for pseudosupercapacitor application. Carbon nanofibers were grown using thermal chemical vapour deposition method with aid of copper nanoparticles as the catalysts. Manganese dioxide was electrochemically deposited on diamond electrode at a constant potential. The charge consumed during the deposition was applied to control the amount and the thickness of manganese dioxide on the diamond electrode. The performance of two capacitors will be shown in details. The comparison of carbon nanofibers based double layer capacitor with manganese dioxide based pseudosupercapacitor as well as with those related capacitors shown in literature will be conducted. More regarding the life-time of these capacitors, power and energy densities, etc. will be discussed as well.

R.R.18
17:30
Authors : Yanying Wang; Rui Li;Chunya Li*
Affiliations : College of Chemistry and Materials Science, South–Central University for Nationalities

Resume : 1,3-di(4-amino-1-pyridinium) propane tetrafluoroborate ionic liquid (DAPPT) was successfully synthesized and characterized by NMR, HPLC-MS. DAPPT was used as a modifier to functionalize reduced graphene oxide (rGO) nanosheets. DAPPT-rGO nanosheets and tyrosinase (Tyr) were thoroughly mixed, and coated to glassy carbon electrode to fabricate a Tyr-DAPPT-rGO/GCE modified electrode, which would be a promising biosensor for phenolic compounds. The as-prepared modified electrodes were characterized with scanning electronic microscopy and electrochemical impedance spectroscopy. Using bisphenol A (BPA) as a target molecule, a number of key factors including the volume of Tyr-DAPPT-rGO solution, the applied potential, pH values and temperature that influence the analytical performance of the biosensor were investigated. The biosensor gave a linear response on the BPA concentration in the range of 1.0 × 10-9 ~ 3.8 × 10-5 molL-1. The detection limits were estimated to be 3.5 × 10-10 molL-1 (S/N=3). Practical application of the biosensor was demonstrated by the determination of BPA leaching from commercial plastic drinking bottles. Results indicated that Gr-DAPPT based interface would be a promising platform for biosensor preparation.

R.R.20
17:30
Authors : Lijun Li, Xiaoyan Wang, Shujuan Wang, Yanfang Gao*, Jinrong Liu
Affiliations : College of Chemical Engineering, Inner Mongolia University of Technology

Resume : Active carbon derived from lignite was activated by ZnCl2, which showed high double capacity performance in a three electrode system. The result of SEM and BET refered that the material activated with ZnCl2 has more meso-pore than that activated with NaOH. Electrochemical investigations indicate that the activated carbon shows the maximum specific capacitance of 207.5Fg−1 in 6M KOH electrolytes at 0.5A g−1, respectively. The capacitor use activated carbon as electrode presents good cycle stability during 3,000 cycles at a fair current density of 5 A g−1 and capacity rate can reach 91%, because of its specific surface area of 1024 m2 / g.

R.R.22
17:30
Authors : Xili Tong, Xiaoning Guo, Xiangyun Guo*
Affiliations : State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, PR China.

Resume : Vertically oriented TiO2 nanotube arrays (TNTAs) were conformally coatedwith an ultrathin nitrogen-doped (N-doped) carbon filmvia the carbonization of a polyimide filmdeposited bymolecular layer deposition and simultaneously hydrogenated, thereby creating a core/shell nanostructure with a precisely controllable shell thickness. The core/shell nanostructure provides a larger heterojunction interface to substantially reduce the recombination of photogenerated electron–hole pairs, and hydrogenation enhances solar absorption of TNTAs. In addition, the N-doped carbon film coating acts as a high catalytic active surface for oxygen evolution reaction, as well as a protective film to prevent hydrogen-treated TiO2 nanotube oxidation by electrolyte or air. As a result, the N-doped carbon film coated TNTAs displayed remarkably improved photocurrent and photostability. The TNTAs with a N-doped carbon film of 1 nm produces a current density of 3.6 mA cm2 at 0 V vs. Ag/AgCl under the illumination of AM 1.5G (100 mW cm2 ), which represents one of the highest values achieved with modified TNTAs. Therefore, we propose that ultrathin N-doped carbon film coating on materials is a viable approach to enhance their PEC water splitting performance.

R.R.23
Start atSubject View AllNum.
 
Carbon for photoelectrochemistry : Paul May
09:00
Authors : Yong Liu, Yuhan Zhu, Kai Yan, Okoth Otieno Kevin, Jingdong Zhang *
Affiliations : School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, P. R. China

Resume : As a newly emerged but promising analytical technique, photoelectrochemical (PEC) detection based on photon-to-electricity conversion has attracted considerable interest due to its high sensitivity as well as simple and cheap instrumentation. To fabricate PEC sensors, various photoactive materials have been explored as transducer species which can convert photoirradiation to electronic response. Among various photoactive materials, graphite-like carbon nitride (g-C3N4) and graphene quantum dots (GQDs) can represent the new carbon nanomaterials-based photocatalysts that possess high photon-to-electricity conversion efficiency under visible light irradiation. We employed g-C3N4 and GQDs to construct two aptamer sensors, respectively, for PEC determination of kanamycin and chloramphenicol. On the other hand, graphene (GR) possesses high electrical conductivity. When GR was doped into CdS QDs, the PEC performance was obviously promoted. Based on the hybrid film of GR-CdS QDs, PEC sensors for 4-aminophenol, catechol and p-phenylenediamine were successfully developed.

R.6.1
09:30
Authors : Meichuan Liu, Jing Yu, Xue Ding, Guoqiang Wang, Guohua Zhao
Affiliations : Department of Chemistry, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, 1239 Siping Road, Shanghai, 200092, China

Resume : Graphene is a monolayer of tightly packed carbon atoms that possesses many interesting physical, chemical, electric and optical properties and has many exciting applications. Microcystin-LR (MC-LR), as inert electrochemical species released by cyanbacteria during eutrophication, is hard to be detected by a simple and direct electrochemical method. In our recent studies, an electrochemical aptasensing strategy based on enzyme assisted graphene assembly signal cycling amplification towards MC-LR has been proposed. Graphene is used in the system with bi-functions. It is first used to adsorb MC-LR binding aptamer to form aptamer-graphene (Apt-G) composites due to the strong - interaction. Once there’s target MC-LR in the system, the aptamer will be grasped by MC-LR and desorpt from graphene surface, leaving “naked” graphene in the solution, which can assemble onto MCH/Au because of the hydrophobic interaction and  conjunction, and can turn on the electron transfer route, resulting in signal generation and electrochemical quantification of MC-LR. Also, another photoelectrochemical aptasensor for MC-LR have been designed and constructed on graphene functionalized TiO2 nanotubes. Graphene is successfully grown onto highly ordered TiO2 nanotubes by a Clicked Chemistry way. MC-LR binding aptamers are further assembled via - interaction resulted from graphene. A promising photoelectrochemical aptasensing platform towards MC-LR under visible-light illumination has thus been provided on the graphene functionalized TiO2 NTs. (Acknowledgements: National Natural Science Foundations of China (NSFC) (No. 21377092)

R.6.2
09:45
Authors : Mailis M. Lounasvuori, Martin Rosillo-Lopez, Christoph G. Salzmann, Daren J. Caruana and Katherine B. Holt
Affiliations : Department of Chemistry, University College London, 20 Gordon St, London WC1H 0AJ, United Kingdom

Resume : Graphene nanoflakes (GNF) with lateral dimensions of ca. 30 nm and edge-terminated with carboxylic acid (COOH) or amide functionalities have been characterised electrochemically after drop-coating onto a boron-doped diamond (BDD) electrode. In the presence of the outer-sphere redox probe ferrocene methanol there is no discernible difference in electrochemical response between the clean and GNF-modified BDD. When hydroquinone or ferricyanide are used as redox probes there is a marked difference in response at the COOH-terminated GNF electrode compared to the unmodified BDD and BDD modified with amide-terminated GNF. The response of the COOH-terminated GNF electrode is highly pH dependent, with significant differences in response noted at pH < 8, where partial protonation of the acid groups is observed. The protonation state of the GNF influences the oxidation mechanism of hydroquinone and in particular the number of solution protons involved in the redox reaction. The voltammetric response of ferricyanide is inhibited at COOH-terminated GNF electrode at pH < 8, especially in low ionic strength solution. The redox reaction is much less influenced by the presence of GNF in D2O, highlighting the role played by readily available protons in destabilising the ferri/ferrocyanide couple. In the presence of GNF in solution, an additional, very intense cyanide stretch IR band is observed and attributed to the formation of a new, non-soluble species.

R.6.3
10:00
Authors : Xili Tong, Xiaoning Guo, Xiangyun Guo
Affiliations : Institute of Coal Chemistry, Chinese Academy of Sciences

Resume : Efficient electrocatalysts of copper nanoparticles with 5−15 nm mean size range on graphene support are successfully developed for controllably catalyzing CO2 electroreduction reactions, and their catalytic activity and selectivity during CO2 electroreduction were analyzed and compared to a bulk Cu electrode. An obvious increase in the catalytic activity was observed with decreasing Cu particle size. This is likely due to an increase in the fraction of under-coordinated sites, such as corners, edges, and defects, as the nanoparticles become smaller.

R.6.4
11:30
Authors : P. Niedziałkowski1, R. Bogdanowicz2, P. Zięba1, A. Cirocka1, T. Ossowski1
Affiliations : 1Department of Analytical Chemistry, Faculty of Chemistry, University of Gdansk, Poland 2Department of Metrology and Optoelectronics, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, Poland

Resume : Nanocrystalline boron-doped diamond (B-NCD) electrodes have very interesting properties for electroanalysis. The detection of nucleobases and polynucleotides based on molecular recognition process can be performed on the B-NCD electrodes by immobilizing of organic molecules deposited directly on the electrode surface. This modification gives the possibility to obtain the electrochemical signals on a decent level of detection. Modification of B-NCD surface electrode by melamine gives the possibility of determining organic molecules such as: pyrimidines and purines. This modification mediates the oxidation process of nucleic acid bases enhancing charge transfer between the electrolyte and the electrode. This work describes electrochemical method of B-NCD surface modification by melamine to obtain organic film. Deposited in this way organic monolayer can be used to create biosensor for amperometric detection and determination selected nucleobases (e.g. thymine, guanine). The modification with melamine significantly increased the working potential range of the B-NCD electrodes compared to the unmodified electrodes. Cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) were used to characterize the obtained monolayer formed on the B-NCD electrode surface. The synthesis of polyamine layer on the B-NCD surface caused a significant broadening of the electrochemical window in both cathodic and anodic areas. Amperometric techniques were used for determination of the limit of detection and limit of quantification of different nucleobases on modified electrodes.

R.7.2
15:00
Authors : Bao-Ping Qi, Dai-Wen Pang*
Affiliations : Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, The Institute for Advanced Studies, and Wuhan Institute of Biotechnology, Wuhan University, Wuhan, 430072, P. R. China

Resume : The abundant oxygenic groups, such as -COOH, -OH, -C-O-C-, -C=O, on graphene quantum dots (GQDs) will be in favour of its functionalization. However, the oxygenic group of ortho-quinone structures characteristic of high activity has been rarely reported. Especially, the direct evidence regarding ortho-quinone structures at the edge of GQDs is needed. By adopting electrochemical method to study GQDs, a pair of reversible redox peaks with a formal potential at 0.29 V and an irreversible oxidation peak can be detected in phosphate buffer solution (PBS). A pair of symmetrical redox peaks could be attributed to peripheral functional moieties at the edge of GQDs that are analogous to ortho-quinone derivatives. As oxidation degree during the preparation of GQDs increased, the ortho-quinone structures would be damaged to a large extent. The moderate oxidation conditions are beneficial to production of ortho-quinone structures. Based on the high specificity of the acid-catalyzed dehydration reaction between ortho-quinones and 1,2-diamines, an efficient route via such a convenient reaction has been developed to modulate photoluminescence emissions of GQDs in our group.

R.8.4
 
Carbon Composite : Xin Jiang
16:00
Authors : Ieva Kranauskaite 1, Jan Macutkevic 1, Juras Banys 1, Vladimir L. Kuznetsov 2, Sergey I. Moseenkov 2
Affiliations : 1 - Department of Radiophysics, Vilnius University, Vilnius, Lithuania 2 - Boreskov institute of Catalysis SB RAS, Novosibirsk, Russia

Resume : Dielectric properties of carbon nanotubes (CNT) composites were investigated very often, mainly in order to find an electrical percolation. However, the relation between CNT microscopic parameters (like length or diameter), CNT preparation technique, polymer matrix parameters and percolation threshold in composites up to now is not clear [1]. Therefore, before experiment it rather impossible to predict dielectric properties of CNT composites. Generally, it expected that percolation threshold is directly proportional to CNT length/diameter aspect ratio, however this relation experimentally was never observed and more complicated formula were used in order to establish influence of aspect ratio on percolation threshold in composites. In this presentation results of dielectric investigations of Polymethylmethacrylate (PMMA) matrix composites filled with multiwalled carbon nanotubes (MWCNT) will be presented and discussed in wide frequency (20 Hz - 3 THz) and temperature (30 K – 450 K) range. This research is supported by European Social Fund under Global Grand Fund. [1] W. Bauhofer, J. Z. Kovacs, A review and analysis of electrical percolation in carbon nanotube polymer composite, Composite Science and Technology 69, 1486 (2009).

R.8.5
16:15
Authors : A.Mukhtarov, S.Usmanova, S.Kalandarova, H.Akbarov
Affiliations : National university of Uzbekistan, Institute of nuclear physics of Uzbekistan Academy of Sciences

Resume : Carbon and silicon nanotubes are unique hydrogen-accumulating and transport systems. But the desorption of hydrogen from nanotubes is problematic. Influence of various external factors on the strength of hydrogen bonding with the lattice will help you find ways to release hydrogen from nanotubes. These external factors are the charge state of the tubes, mechanical force and others. In this study, we investigated the phenomenon of hydrogen bonding in carbon and silicon nanotubes and the study of microscopic factors on the binding energy of hydrogen in nanotubes by computer simulation an nonconventional tight-binding method and molecular dynamics. Our results show that the carbon nanotube binds weakly hydrogen molecule compared to a silicon tube. Zigzag-type nanotubes tightly connected with the hydrogen spiral tube least active. Increasing tube diameter reduces the hydrogen bonding. Among the structural lattice distortions, open position most strongly binds hydrogen bend tube has minimal value and the smallest value pentagon bond energy Si-H. The excess negative charge weakens the connection wall and the H2 molecule. Giving negative charge of the nanotube, it can be distinguished from the hydrogen gas.

R.8.6
16:45
Authors : Hao Zhuang, Nianjun Yang*, Lei Zhang, Regina Fuchs, Xin Jiang*
Affiliations : Institute of Materials Engineering, University of Siegen, 57076 Siegen, Germany

Resume : Silicon carbide (SiC), a wide band gap material, has been considered for many different applications such as for powder devices. Due to its rich surface properties and the possibility to be functionalized, SiC has been paid attention recently for electrochemical and biochemical applications. In this presentation, we will show the growth and properties of nanocrystalline, microcrystalline and epitaxial (001) 3C-SiC films using microwave plasma chemical vapor deposition technique under different conditions. Especially electrochemical properties of these films will be shown in detail, regarding electrochemical potential windows, capacitance, redox activities. Based on these properties, the applications of different SiC films as dopamine electrochemical sensor and electrochemical capacitor will be summarized. Further surface functionalization of SiC for DNA biosensing will be outlined as well.

R.8.8
17:00
Authors : Xiaoning Guo,* Xili Tong, Xiangyun Guo
Affiliations : State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, PR China.

Resume : Fisher-Tropsch synthesis (FTS) converts carbon monoxide and hydrogen to liquid fuels and chemicals and is usually operated under high temperature ranges, which results in an evident energy consumption and CO2 emission. A photocatalytic FTS route was proposed to efficiently harvest solar energy. Worm-like ruthenium nanostructures dispersed on graphene sheets can effectively catalyze FTS at mild conditions under irradition of visible light and achieve a catalytic activity as high as 14.4 molcomolRu-1h-1.The reaction rate of FTS can be enhanced by increasing the irradiation tensity of decreasing the irradiation wavelength . The work provides a green and efficient photocatalytic route for FTS.

R.8.9

No abstract for this day

No abstract for this day


Symposium organizers
Chunhai FAN Shanghai Institute of Applied Physics, CAS

Shanghai 201800 China

+86 2139194129
fchh@sinap.ac.cn
John S. FOORDUniversity of Oxford

OX1 3TA, UK.

+44 1865 275967
john.foord@chem.ox.ac.uk
Greg M. SWAINMichigan State University

East Lansing, MI 48824-1322 USA

+1 517 3559715229
swain@chemistry.msu.edu
Yasuaki EINAGAKeio University

Yokohama 223-8522 Japan

+81 455661704
einaga@chem.keio.ac.jp