Electronic Transport and Doping Effects in Reduced Graphene Oxide Measured by Scanning Probe Microscopy

ABSTRACTWe present a Scanning Probe Microscopy study of doping and sensing properties of reduced graphene oxide (rGO)-based nanosensors. rGO devices are created by dielectrophoretic assembly of rGO platelets onto interdigitated electrode arrays, which are lithographically pre-patterned on top of SiO2/Si wafers. The availability of several types of oxygen functional groups allows rGO to interact with a wide range of organic dopants, including methanol, ethanol, acetone, and ammonia. We perform sensitive Scanning Kelvin Probe Microscopy (SKPM) measurements on patterned rGO electronic circuits and show that the local electrical potential and charge distribution are significantly changed when the device is exposed to organic dopants. We also demonstrate that SKPM experiments allow us to quantify the amount of charge transferred to the sensor during chemical doping, and to spatially resolve the active sites of the sensor where the doping process takes place.

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Mapping intrinsic electromechanical responses at the nanoscale via sequential excitation scanning probe microscopy empowered by deep data

National Science Review ◽

10.1093/nsr/nwy096 ◽

2018 ◽

Vol 6 (1) ◽

pp. 55-63 ◽

Cited By ~ 17

Author(s):

Boyuan Huang ◽

Ehsan Nasr Esfahani ◽

Jiangyu Li

Keyword(s):

Scanning Probe Microscopy ◽

Data Analytics ◽

Electromechanical Coupling ◽

Principal Component ◽

Scientific Data ◽

Scanning Probe ◽

Physical Analysis ◽

Brute Force ◽

Probe Microscopy ◽

Wide Range

Abstract Ever-increasing hardware capabilities and computation powers have enabled acquisition and analysis of big scientific data at the nanoscale routine, though much of the data acquired often turn out to be redundant, noisy and/or irrelevant to the problems of interest, and it remains nontrivial to draw clear mechanistic insights from pure data analytics. In this work, we use scanning probe microscopy (SPM) as an example to demonstrate deep data methodology for nanosciences, transitioning from brute-force analytics such as data mining, correlation analysis and unsupervised classification to informed and/or targeted causative data analytics built on sound physical understanding. Three key ingredients of such deep data analytics are presented. A sequential excitation scanning probe microscopy (SE-SPM) technique is first developed to acquire high-quality, efficient and physically relevant data, which can be easily implemented on any standard atomic force microscope (AFM). Brute-force physical analysis is then carried out using a simple harmonic oscillator (SHO) model, enabling us to derive intrinsic electromechanical coupling of interest. Finally, principal component analysis (PCA) is carried out, which not only speeds up the analysis by four orders of magnitude, but also allows a clear physical interpretation of its modes in combination with SHO analysis. A rough piezoelectric material has been probed using such a strategy, enabling us to map its intrinsic electromechanical properties at the nanoscale with high fidelity, where conventional methods fail. The SE in combination with deep data methodology can be easily adapted for other SPM techniques to probe a wide range of functional phenomena at the nanoscale.

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Facile Fabrication of CeO2/Electrochemically Reduced Graphene Oxide Nanocomposites for Vanillin Detection in Commercial Food Products

Nanomaterials ◽

10.3390/nano10071356 ◽

2020 ◽

Vol 10 (7) ◽

pp. 1356 ◽

Cited By ~ 2

Author(s):

Xue Nie ◽

Rui Zhang ◽

Zheng Tang ◽

Haiyan Wang ◽

Peihong Deng ◽

...

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Linear Sweep Voltammetry ◽

X Ray ◽

Transmission Electron ◽

Reduced Graphene ◽

Electrochemically Reduced Graphene Oxide ◽

Wide Range ◽

Facile Fabrication

In this paper, CeO2 nanoparticles were synthesized by the solvothermal method and dispersed uniformly in graphene oxide (GO) aqueous solution by ultrasonication. The homogeneous CeO2-GO dispersion was coated on the surface of a glassy carbon electrode (GCE), and the CeO2/electrochemically reduced graphene oxide modified electrode (CeO2/ERGO/GCE) was obtained by potentiostatic reduction. The results of X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) showed that CeO2 nanocrystals were uniformly coated by gossamer like ERGO nanosheets. The electrochemical behavior of vanillin on the CeO2/ERGO/GCE was studied by cyclic voltammetry (CV). It was found that the CeO2/ERGO/GCE has high electrocatalytic activity and good electrochemical performance for vanillin oxidation. Using the second derivative linear sweep voltammetry (SDLSV), the CeO2/ERGO/GCE provides a wide range of 0.04–20 µM and 20 µM–100 µM for vanillin detection, and the detection limit is estimated to be 0.01 µM after 120 s accumulation. This method has been successfully applied to the vanillin detection in some commercial foods.

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The Role of Actin-Binding Protein Filamin A in Cellular Stiffness and Morphology Studied by Wide-Range Scanning Probe Microscopy

Japanese Journal of Applied Physics ◽

10.1143/jjap.45.2328 ◽

2006 ◽

Vol 45 (3B) ◽

pp. 2328-2332 ◽

Cited By ~ 4

Author(s):

Kosaku Kato ◽

Yukiko Ohmori ◽

Takeomi Mizutani ◽

Hisashi Haga ◽

Kazuyo Ohashi ◽

...

Keyword(s):

Scanning Probe Microscopy ◽

Binding Protein ◽

Scanning Probe ◽

Actin Binding ◽

Filamin A ◽

Probe Microscopy ◽

Actin Binding Protein ◽

Wide Range ◽

Range Scanning

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One-Step Solvothermal Synthesis of Tetranitro-Cobalt Phthalocyanine/Reduced Graphene Oxide Composite

NANO ◽

10.1142/s1793292015500459 ◽

2015 ◽

Vol 10 (03) ◽

pp. 1550045 ◽

Cited By ~ 5

Author(s):

Lijuan Zhang ◽

Hejun Li ◽

Qiangang Fu ◽

Zhanwei Xu ◽

Kezhi Li ◽

...

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Rotating Disk ◽

Rotating Disk Electrode ◽

Cobalt Phthalocyanine ◽

Transmission Electron ◽

Reduced Graphene ◽

Wide Range ◽

One Step

Tetranitro-cobalt phthalocyanine/reduced graphene oxide (TNCoPc/RGO) composite was prepared using ethylene glycol as reducing agent and precursor. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the composite. The electrochemical performance of the composite was examined by cyclic voltammetry and rotating disk electrode. The SEM observation and UV-Vis absorption spectrophotometer reveal that TNCoPc nanoparticles are closely contacted with RGO. The results show that the composite has a larger peak current and a higher current density than TNCoPc for oxygen reduction in an alkaline medium. This work offers a simple and environmental route for the synthesis of metal phthalocyanine (MPc)/RGO, which is adaptable to a wide range of applications in fuel cells.

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Ammonia Gas Sensor Based on Aniline Reduced Graphene Oxide

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.669.79 ◽

2013 ◽

Vol 669 ◽

pp. 79-84 ◽

Cited By ~ 15

Author(s):

Xiao Lu Huang ◽

Nan Tao Hu ◽

Yan Yan Wang ◽

Ya Fei Zhang

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Gas Sensor ◽

Chemical Reduction ◽

Electrode Arrays ◽

Ammonia Gas ◽

Reduced Graphene ◽

Vis Spectroscopy ◽

Drop Drying

Here we demonstrate a promising gas sensor based on aniline reduced graphene oxide (RGO), which is fabricated through drop drying RGO nanosheets suspension between the electrode arrays to create conductive networks. RGO, as the sensing materials, which is prepared via the chemical reduction of graphene oxide (GO) by aniline, has been characterized by infrared spectroscopy, UV-Vis spectroscopy, transmittance electron microscopy and scanning electron microscopy. The sensing properties of RGO have also been studied, and the results show that RGO reduced from aniline (RGO-A) exhibits an excellent response to ammonia gas (NH3). Comparing with the RGO reduced from hydrazine (RGO-H) and polyaniline (PANI) nanofiber, the RGO-A exhibits a much better response to NH3 gas. The response of the sensor based on RGO-A to 50 ppm NH3 gas exhibits about 9.2 times and 3.5 times higher than those of the device based RGO-H and PANI nanofiber respectively. In addition, the RGO-A sensor exhibits an excellent repeatability and selectivity to NH3 gas. The oxidized aniline, i.e., polyaniline, which is attached on the surface of RGO sheets through π–π interaction, plays important roles in the final sensing performance of the device, and benefits for the application of the sensor in the field of NH3 gas detection.

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Graphene/Reduced Graphene Oxide-Carbon Nanotubes Composite Electrodes: From Capacitive to Battery-Type Behaviour

Nanomaterials ◽

10.3390/nano11051240 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1240

Author(s):

Olena Okhay ◽

Alexander Tkach

Keyword(s):

Carbon Nanotubes ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Electrode Materials ◽

Electrical Energy ◽

Portable Devices ◽

Composite Electrodes ◽

Mechanical Pressure ◽

Reduced Graphene ◽

Wide Range

Thanks to the advanced technologies for energy generation such as solar cells and thermo- or piezo-generators the amount of electricity transformed from light, heat or mechanical pressure sources can be significantly enhanced. However, there is still a demand for effective storage devices to conserve electrical energy which addresses the wide range of large stationary applications from electric vehicles to small portable devices. Among the large variety of energy-storage systems available today, electrochemical energy sources and, in particular, supercapacitors (SC), are rather promising in terms of cost, scaling, power management, life cycle and safety. Therefore, this review surveys recent achievements in the development of SC based on composites of such carbon-derived materials as graphene (G) and reduced graphene oxide (rGO) with carbon nanotubes (CNT). Various factors influencing the specific capacitance are discussed, while specific energy and power as well as cycling stability of SC with G/rGO-CNT composite electrode materials are overviewed.

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Probing host-guest interactions in hydroxyapatite intercalated graphene oxide nanocomposite: NMR and scanning probe microscopy studies

Chemical Physics Letters ◽

10.1016/j.cplett.2019.136636 ◽

2019 ◽

Vol 732 ◽

pp. 136636

Author(s):

A. Rajesh ◽

G. Mangamma ◽

T.N. Sairam ◽

S. Subramanian

Keyword(s):

Graphene Oxide ◽

Scanning Probe Microscopy ◽

Scanning Probe ◽

Probe Microscopy

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Fabrication of Reduced Graphene Oxide-Ag Nanocomposites and Analysis on the Interaction with BSA

Journal of Nanomaterials ◽

10.1155/2019/2707909 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Huali Zhang ◽

Wen Liu ◽

Linqing Yang ◽

Jun Liu ◽

Yunfei Wang ◽

...

Keyword(s):

Silver Nanoparticles ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Scanning Probe Microscopy ◽

Chemical Reduction ◽

Binding Reaction ◽

Transmission Electron ◽

Reduced Graphene ◽

Quenching Process ◽

Different Temperatures

Graphene is an excellent platform to support and stabilize silver nanoparticles (AgNPs). The reduced graphene oxide-silver nanoparticles (rGO-AgNPs) were synthesized by the chemical reduction method and characterized by using ultraviolet-visible (UV-vis) absorption, transmission electron microscopy (TEM), X-ray diffractometer (XRD), and scanning probe microscopy (SPM). The binding reaction of rGO-AgNPs with bovine serum albumin (BSA) was investigated by using fluorescence spectrometry and SPM. As the concentration of AgNPs increased, the fluorescence spectrum was quenched, and the quenching process of rGO-AgNPs and BSA was static quenching. Thermodynamic parameters of the absorption process were evaluated at different temperatures, and the negative values of Gibbs free energy (ΔG) showed that this process was spontaneous. The main type of interaction was hydrophobic interaction according to the values of changes in standard enthalpy (ΔH) and entropy (ΔS). In addition, the morphology changes of proteins interacting with nanomaterials were detected by SPM.

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