scholarly journals Low Surface Roughness Graphene Oxide Film Reduced with Aluminum Film Deposited by Magnetron Sputtering

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1428
Author(s):  
Xiaowei Fan ◽  
Xuguo Huai ◽  
Jie Wang ◽  
Li-Chao Jing ◽  
Tao Wang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Electron Transfer ◽  
Graphene Oxide ◽  
Magnetron Sputtering ◽  
Chemical Reduction ◽  
Graphene Film ◽  
Conductivity Measurement ◽  
Electrical Conductivity Measurement ◽  
Vis Spectroscopy ◽  
Hcl Solution

Graphene film has wide applications in optoelectronic and photovoltaic devices. A novel and facile method was reported for the reduction of graphene oxide (GO) film by electron transfer and nascent hydrogen produced between aluminum (Al) film deposited by magnetron sputtering and hydrochloric acid (HCl) solution for only 5 min, significantly shorter than by other chemical reduction methods. The thickness of Al film was controlled utilizing a metal detection sensor. The effect of the thickness of Al film and the concentration of HCl solution during the reduction was explored. The optimal thickness of Al film was obtained by UV-Vis spectroscopy and electrical conductivity measurement of reduced GO film. Atomic force microscope images could show the continuous film clearly, which resulted from the overlap of GO flakes, the film had a relatively flat surface morphology, and the surface roughness reduced from 7.68 to 3.13 nm after the Al reduction. The film sheet resistance can be obviously reduced, and it reached 9.38 kΩ/sq with a high transmittance of 80% (at 550 nm). The mechanism of the GO film reduction by electron transfer and nascent hydrogen during the procedure was also proposed and analyzed.

Effect of Sputtering Pressure on Optimization of Titanium Dioxide Nanostructures Prepared by RF Magnetron Sputtering

2013 ◽  
Vol 667 ◽  
pp. 452-457 ◽  
Author(s):  
N.A.M. Asib ◽  
Mohamed Zahidi Musa ◽  
Saifollah Abdullah ◽  
Mohamad Rusop
Keyword(s):  
Surface Roughness ◽  
Titanium Dioxide ◽  
Magnetron Sputtering ◽  
Visible Region ◽  
Rf Magnetron Sputtering ◽  
Transmission Spectra ◽  
Cross Sectional ◽  
Vis Spectroscopy ◽  
Sputtering Pressure ◽  
Tio2 Nanostructures

Titanium dioxide (TiO2) nanostructures were deposited on glass substrate by Radio Frequency (RF) magnetron sputtering. The samples deposited at various sputtering pressures and annealed at 723 K, were characterized using Atomic Force Microscope (AFM) to observe the surface morphology and topology, roughness properties and cross-sectional of TiO2 nanostructures, Field Emission Scanning Electrons Microscope (FESEM) to observe the particle sizes of TiO2 nanostructures and UV-vis spectroscopy to record the UV-vis transmission spectra. The aim of this paper is to determine which parameter of sputtering pressures influence the optimization of TiO2 nanostructures. AFM images show that the surface roughness of the samples decreases as the working pressures of sputtering increases. From FESEM images, it can be deduced that the higher the sputtering pressure, the smaller the particle size is. All the samples are highly transmittance with an average transmittance higher than 80% in the visible region as recorded by UV-vis transmission spectra. The relatively high transmittance of the sample indicates its low surface roughness and good homogeneity. For optimum TiO2 nanostructures deposited at various RF pressures it has the lowest surface roughness and the smallest TiO2 size particles with the indirect optical band gap of 3.41 eV.

Ammonia Gas Sensor Based on Aniline Reduced Graphene Oxide

2013 ◽  
Vol 669 ◽  
pp. 79-84 ◽  
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.

scholarly journals Formation and Characterization of Copper Nanocube-Decorated Reduced Graphene Oxide Film

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
M. Z. H. Khan ◽  
M. A. Rahman ◽  
P. Yasmin ◽  
F. K. Tareq ◽  
N. Yuta ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Indium Tin Oxide ◽  
Chemical Reduction ◽  
Device Fabrication ◽  
Simple Method ◽  
Force Microscopy ◽  
Reduced Graphene ◽  
Vis Spectroscopy ◽  
The Individual

In this study, we present a new approach for the formation and deposition of Cu nanocube-decorated reduced graphene oxide (rGO-CuNCs) nanosheet on indium tin oxide (ITO) electrode using very simple method. Cubic Cu nanocrystals have been successfully fabricated on rGO by a chemical reduction method at low temperature. The morphologies of the synthesized materials were characterized by ultraviolet-visible (UV-vis) spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and atomic force microscopy (AFM). The as-formed CuNCs were found to be homogeneously and uniformly decorated on rGO nanosheets. We demonstrated that the individual rGO sheets can be readily reduced and decorated with CuNCs under a mild condition using L-ascorbic acid (L-AA). Such novel ITO/rGO-CuNCs represent promising platform for future device fabrication and electrocatalytic applications.

Investigation of the Influences of Reaction Temperature and Time on the Chemical Reduction of Graphene Oxide by Conventional Method Using Vitamin C as a Reducing Agent

2017 ◽  
Vol 909 ◽  
pp. 225-230
Author(s):  
Chaval Sriwong ◽  
Kittisak Choojun ◽  
Samart Kongtaweelert
Keyword(s):  
Graphene Oxide ◽  
Vitamin C ◽  
Reaction Temperature ◽  
Chemical Reduction ◽  
Aqueous Suspension ◽  
Heating Time ◽  
Reducing Agent ◽  
Conventional Heating ◽  
Vis Spectroscopy ◽  
Ft Ir

The aim of this work is to investigate the synthesis of reduced graphene oxide (rGO) aqueous suspension by a conventional heating method using vitamin C as a reducing agent. The influences of reaction temperatures (70, 90 and 100 °C) and heating times (30, 45 and 60 min) on the chemical reduction of graphene oxide (GO) were studied. Then, the obtained rGO samples were characterized by FT-IR, Raman and UV-Vis spectroscopy. The FT-IR and Raman results showed that the reduction degree of GO to rGO was increased with the rising of the reaction temperature and time. Moreover, the UV-Vis spectra demonstrated that the absorption band at around 230 nm (π-π*) of pristine GO had shift to the longer wavelength upon the chemical reduction, indicating that GO is reduced to rGO. The optimal condition of the chemical reduction of GO to achievable rGO was the temperature of 90 °C with the 45 min of heating time. This condition yielded the rGO black aqueous suspension with the high quality and stability. Thus, this method of synthesis has an advantage of the rGO dispersion which led to many potential applications.

Effect of Chemical Reduction Temperature on Optical Properties of Reduced Graphene Oxide (rGO) and its Potentials Supercapacitor Device

2017 ◽  
Vol 901 ◽  
pp. 55-61 ◽  
Author(s):  
Haris Suhendar ◽  
Ahmad Kusumaatmaja ◽  
Kuwat Triyana ◽  
Iman Santoso
Keyword(s):  
Optical Properties ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Chemical Reduction ◽  
Epoxy Group ◽  
Electrical Energy ◽  
Graphite Powder ◽  
Reduction Temperature ◽  
Reduced Graphene ◽  
Vis Spectroscopy

Reduced graphene oxide (rGO) has been successfully synthesized from graphite powder using Hummer’s Method. The epoxy group in GO structure was reduced by hydrazine 80 wt% at a temperature of 70o, 80o, and 90°C. The optical properties of produced rGO were characterized by using Uv-Vis and FTIR spectrometer. From Uv-Vis spectroscopy we observe that the absorbance of rGO decreased as increasing the reduction temperature. This is because the higher reduction temperature yields a high degree of rGO defect. The rGO produced at a reduction temperature of 70oC has very close similiraties absorbance spectrum with rGO produced by Sigma Aldrich Company. The Uv-Vis absorbance of rGO was used to calculated optical constant, and by using Kramers-Kronig relation we got refractive index values of rGO. The decreasing of absorbance may also stem out from the reducing of C=C bonding with sp2 hybridization due to the presence of energetic Hydrazine as indicated by the decrease of FTIR spectrum at ~1600 cm-1. Our produced rGO then used to fabricated the supercapacitor device with a mass of 0,03 gram using Polivinyl Alcohol (PVA) as a binder. From cyclic voltammetry measurement, we obtain the specific capacitance of our rGO-based supercapacitor is 2.45 F which is still in the category of supercapacitive although the optimization of rGO and PVA composition is still required. Our result shows the exciting potential of rGO based supercapacitor as electrical energy storage.

Nanostructural Characteristics and Electrical Conductivity of Copper Nanoparticles-Polypropylene Nanocomposites for Bipolar Plate Application

2013 ◽  
Vol 634-638 ◽  
pp. 2214-2217
Author(s):  
Sari Katili ◽  
Akhmad Herman Yuwono
Keyword(s):  
Electrical Conductivity ◽  
Copper Nanoparticles ◽  
Production Cost ◽  
Conductivity Measurement ◽  
Bipolar Plate ◽  
Electrical Conductivity Measurement ◽  
Wet Chemistry ◽  
Polypropylene Nanocomposites ◽  
Vis Spectroscopy ◽  
Polypropylene Matrix

The current research is aimed at obtaining suitable nanocomposites for bipolar plate application in fuel cell, which fulfill the requirement for electrical and mechanical properties and low production cost. For this purpose, copper nanoparticles (Cu-NPs) were embedded in polypropylene matrix through wet-chemistry technique with the presence of polypropylene-grafted maleic anhydride as the coupling agent. The resulting nanocomposites were characterized with UV-Vis spectroscopy, TEM, SEM, TGA and electrical conductivity measurement. It was found that the addition of Cu-NPs up to 1.50 wt% has improved effect on the electrical conductivity up to 14.43 S/cm. However, further increase of Cu-NPs loading to 2.00 wt% adversely reduced the electrical conductivity down to 9.31 S/cm, as a consequence of severe agglomeration and large pores formation.

Comparison of Optical Characteristics of GO-PANI Composite in Solution and Thin Film

2021 ◽  
Vol 1028 ◽  
pp. 285-290
Author(s):  
Levia Annisa Fitriantika ◽  
Diyan Unmu Dzujah ◽  
Rahmat Hidayat ◽  
Norman Syakir ◽  
Fitrilawati
Keyword(s):  
Electron Transfer ◽  
Thin Layers ◽  
Optical Characteristics ◽  
Emeraldine Base ◽  
Electrostatic Charges ◽  
Pani Composite ◽  
Reduced Graphene ◽  
Vis Spectroscopy ◽  
Quartz Substrates ◽  
Hcl Solution

Reduced Graphene Oxide (rGO) is a promising material as an active electrodes material for supercapacitors. However, in its application, rGO can only store electrostatic charges so there is no electron transfer between surface of the electrode and electrolyte. In order to improve electrode performance, rGO can be composite with conductive polymers such Polyaniline (PANi). It was reported that rGO-PANi composite can increase conductivity of rGO and support pseudocapacitance of the material so the electron transfer can be carried out actively through reduction-oxidation (redox) reactions. In this work we study preparation of rGO-PANI composite using UV oven spraying method. Thin layers of rGO-PANi composite were prepared from mixture of 0.5 mg/ml GO dispersion (Graphenia) and PANi-HCl solution with a ratio of 1:1. PANi-HCl solution were prepared from PANi Emeraldine Base and 1 M HCl with mole ratio of 1:2. The samples were spray coated onto quartz substrates under photo-irradiation using UV Oven Spraying apparatus. In order to obtain a proper thickness for electrode application we varied deposition repetition. The optical characteristics of the rGO-PANi composites were measured using UV-Vis Spectroscopy. The results were compared with the optical spectra of rGO and PANi, respectively. Acknowledgement This work was funded by Hibah Kemenristek Dikti Indonesia, contract no: 1827/UN6.3.1/LT/2020 date 12 May 2020.

scholarly journals Investigation of chemical reduction of graphene oxide with many reduced agents

2015 ◽  
Vol 18 (2) ◽  
pp. 197-210
Author(s):  
Tam Thanh Mai ◽  
Nhan Thuc Chi Ha ◽  
Van Thi Thanh Khuat ◽  
Huy Thuc Ha
Keyword(s):  
Graphene Oxide ◽  
Graphite Oxide ◽  
Chemical Reduction ◽  
Graphene Film ◽  
Reduction Process ◽  
Reducing Agents ◽  
Reducing Agent ◽  
X Ray Diffraction ◽  
Analysis Methods ◽  
Reducing Ability

Graphene based on graphite oxide prepared by chemical reduction method is always interesting for scientists since the early days of discovery of graphene. Many different reducing agents are recommended, however every reducing agent is only active on one type of functional groups on the structure of graphene oxide. For studying clearly the reducing ability of the chemical reducing agent, this research has focused on investigating the possibility of 3 reducing agents such as N2H4, NaBH4 and HI. Besides, polyethylene oxide is also used as modified agent to completely exfoliate of graphite oxide before continuing the reduction process. Based on spectral analysis methods such as Fourier transform infrared (FTIR), UV-Vis and Raman spectroscopy, we have demonstrated the reduced ability of each agent, and strong reducing agent is HI. Exfoliated structure of MGO-PEG and graphene is demonstrated by means of X-ray diffraction analysis and scanning (SEM) and transmittance (TEM) electron microscopy. The thermal analysis methods such as TGA and DSC also contribute to clarify the role of each reducing agent. Finally, the four-probe method was used to determine the sheets resistance of the graphene film: RGO-HI (120 Ω/square), RGO-Na (1300 Ω/square) and RGO-Hz (1500 Ω/square). This study contributes to clarify the reducing ability of N2H4, NaBH4 and HI on the same kind of graphene oxide that has not yet been studied.

scholarly journals Synthesis, Growth, and Electrical Transport Properties of Pure and -Doped Triglycine Sulphate Crystal

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Farhana Khanum ◽  
Jiban Podder
Keyword(s):  
Electrical Transport ◽  
Conductivity Measurement ◽  
Electrical Transport Properties ◽  
Electrical Conductivity Measurement ◽  
Triglycine Sulphate ◽  
Direct Current Conductivity ◽  
Vis Spectroscopy ◽  
Vicker’S Microhardness ◽  
Dielectric Loss Increase

Pure triglycine sulphate (TGS) and LiSO4-doped TGS crystals were grown from aqueous solution by natural evaporation method. The grown crystals were characterized by UV-vis spectroscopy, electrical conductivity () measurement, dielectric studies, microhardness, and thermogravimetry/differential thermal analysis. Pure TGS and LiSO4-doped TGS crystals were found highly transparent and full faced. The direct current conductivity is found to increase with temperature as well as dopant concentrations. Curie temperature remains the same for pure and doped crystals, but dielectric constant and dielectric loss increase with dopant concentration. The Vicker’s microhardness of the LiSO4-doped TGS crystals along (001) face is found higher than that of pure TGS crystals. Etching studies illustrate the quality of the doped crystal. The experimental results evidence the suitability of the grown crystal for optoelectronic applications.

Improving surface roughness of the 3D printed part using electroless plating

2017 ◽  
Vol 233 (5) ◽  
pp. 942-954
Author(s):  
Nitesh Kumar Dixit ◽  
Rajeev Srivastava ◽  
Rakesh Narain
Keyword(s):  
Surface Roughness ◽  
Room Temperature ◽  
Conductivity Measurement ◽  
Acrylonitrile Butadiene Styrene ◽  
Copper Deposition ◽  
Electrical Performance ◽  
Electrical Conductivity Measurement ◽  
First Case ◽  
3D Printed ◽  
Butadiene Styrene

The effect of electroless metallic coating on 3D printed acrylonitrile–butadiene–styrene plastic parts surface has been studied. Owing to its excellent toughness, good-dimensional reliability, good-process capability, chemical resistance and cost-effectiveness, acrylonitrile–butadiene–styrene is used for fabrication of parts using a 3D open source printer. These parts are further metallic coated using electroless copper deposition technique. Two different surface preparation processes, namely aluminium paint paste and aluminium epoxy paste have been used for electroless coating. After the surface conditioning of parts using these methods, copper is deposited electrolessly using acidic solution, containing 12.5 wt% copper sulphate with 7.5 wt% of sulphuric acid. Deposition of copper, for two different methods, has been carried out using different temperature conditions and different time of deposition. In the first case, the temperature of the solution is initially kept at 45±2 ℃ and is allowed to come to the room temperature as the deposition is completed. In the second case, the temperature of the solution is maintained at room temperature throughout the process. Further, copper-deposited 3D printed parts were characterized based on their surface roughness measurement, electrical conductivity measurement, scanning electron microscopy, energy dispersive spectroscopy and adhesion evaluation test. It has been found that both the methods used for coating show better electrical performance and more uniform copper deposition. Adhesion between copper layers and 3D printed acrylonitrile–butadiene–styrene substrates is found to have good strength for Al-Epoxy-coated parts.

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