scholarly journals RSM-Based Preparation and Photoelectrocatalytic Performance Study of RGO/TiO2 NTs Photoelectrode

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1492
Author(s):  
Jinlong Zuo ◽  
Siying Yuan ◽  
Yiwen Li ◽  
Chong Tan ◽  
Zhi Xia ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Chemical Reduction ◽  
Deposition Potential ◽  
Performance Study ◽  
Simulated Solar Light ◽  
Preparation Conditions ◽  
Reduced Graphene ◽  
Electrochemical Deposition Method ◽  
Tio2 Nts

In this paper, reduced graphene oxide (RGO) was prepared by a modified Hummers method and chemical reduction method, and an RGO/TiO2 NTs (RGO/TiO2 nanotubes) photoelectrode was prepared by the electrochemical deposition method. The as-prepared RGO/TiO2 NTs were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and their photocatalytic activities were investigated by measuring the degradation of methylene blue (MB) under simulated solar light irradiation. The SEM and XRD results indicated that the original tubular structure of TiO2-NTs was not changed after RGO modification. The surface of the TiO2 NTs photoelectrode was covered with a non-uniform, flake-shaped reduced graphene oxide film. The thickness of the RGO/TiO2 NTs was increased to about 22.60 nm. The impedance of the RGO/TiO2 NTs was smaller than that of the TiO2 NT photoelectrode. The optimal preparation conditions of RGO/TiO2 NT photoelectrodes were investigated by using a single factor method and response surface method. The best preparation conditions were as follows: deposition potential at 1.19 V, deposition time of 10.27 min, and deposition temperature at 24.94 °C.

scholarly journals A Facile and Green Synthesis of a MoO2-Reduced Graphene Oxide Aerogel for Energy Storage Devices

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 594 ◽  
Author(s):  
Mara Serrapede ◽  
Marco Fontana ◽  
Arnaud Gigot ◽  
Marco Armandi ◽  
Glenda Biasotto ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Chemical Reduction ◽  
Low Cost ◽  
Xps Analysis ◽  
3D Scaffold ◽  
Energy Storage Devices ◽  
Reduced Graphene

A simple, low cost, and “green” method of hydrothermal synthesis, based on the addition of l-ascorbic acid (l-AA) as a reducing agent, is presented in order to obtain reduced graphene oxide (rGO) and hybrid rGO-MoO2 aerogels for the fabrication of supercapacitors. The resulting high degree of chemical reduction of graphene oxide (GO), confirmed by X-Ray Photoelectron Spectroscopy (XPS) analysis, is shown to produce a better electrical double layer (EDL) capacitance, as shown by cyclic voltammetric (CV) measurements. Moreover, a good reduction yield of the carbonaceous 3D-scaffold seems to be achievable even when the precursor of molybdenum oxide is added to the pristine slurry in order to get the hybrid rGO-MoO2 compound. The pseudocapacitance contribution from the resulting embedded MoO2 microstructures, was then studied by means of CV and electrochemical impedance spectroscopy (EIS). The oxidation state of the molybdenum in the MoO2 particles embedded in the rGO aerogel was deeply studied by means of XPS analysis and valuable information on the electrochemical behavior, according to the involved redox reactions, was obtained. Finally, the increased stability of the aerogels prepared with l-AA, after charge-discharge cycling, was demonstrated and confirmed by means of Field Emission Scanning Electron Microscopy (FESEM) characterization.

Chemically reduced graphene oxide-coated knitted fabric imparted conductivity and outstanding hydrophobicity

2021 ◽  
pp. 004051752199547
Author(s):  
Min Hou ◽  
Xinghua Hong ◽  
Yanjun Tang ◽  
Zimin Jin ◽  
Chengyan Zhu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Chemical Reduction ◽  
Knitted Fabric ◽  
Mesh Structure ◽  
Reduced Graphene ◽  
Chemically Reduced Graphene Oxide ◽  
Modified Hummers Method

Functionalized knitted fabric, as a kind of flexible, wearable, and waterproof material capable of conductivity, sensitivity and outstanding hydrophobicity, is valuable for multi-field applications. Herein, the reduced graphene oxide (RGO)-coated knitted fabric (polyester/spandex blended) is prepared, which involves the use of graphite oxide (GO) by modified Hummers method and in-situ chemical reduction with hydrazine hydrate. The treated fabric exhibits a high electrical conductivity (202.09 S/cm) and an outstanding hydrophobicity (140°). The outstanding hydrophobicity is associated with the morphology of the fabric and fiber with reference to pseudo-infiltration. These properties can withstand repeated bending and washing without serious deterioration, maintaining good electrical conductivity (35.70 S/cm) and contact angle (119.39°) after eight standard washing cycles. The material, which has RGO architecture and continuous loop mesh structure, can find wide use in smart garment applications.

scholarly journals Synthesis and Characterization of Reduced Graphene Oxide (rGO) Started from Graphene Oxide (GO) Using the Tour Method with Different Parameters

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Adere Tarekegne Habte ◽  
Delele Worku Ayele
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Potassium Permanganate ◽  
Chemical Reduction ◽  
Volume Ratio ◽  
Graphite Powder ◽  
Green Approach ◽  
Synthesis Strategy ◽  
Reduced Graphene ◽  
Diffraction Patterns

A new approach to synthesize graphene is oxidizing graphite powder with a mixture of H2SO4/H3PO4 acids and potassium permanganate. Parameters such as reaction time, reaction temperature, and amount of concentration were varied to study the degree of oxidation of graphite to graphene oxide. Currently, an improved method for the preparation of graphene oxide was the most common one. A mixture of H2SO4/H3PO4 (9 : 1 volume ratio) instead of only H2SO4 resulted in increased hydrophilic and oxidized GO without the emission of toxic gas, which differs from the traditional Hummers’ method. The graphene oxide (GO) was converted to reduced graphene oxide (rGO) by chemical reduction using ascorbic acid as the reducing agent. The GO and rGO were characterized by UV-visible spectroscopy, FTIR spectroscopy, and X-ray diffraction patterns. The result showed that treating graphite powder with potassium permanganate (1 : 9) and a mixture of concentrated H2SO4/H3PO4 acids at 50°C for 12 hours resulted in a better oxidation degree. The designed synthesis strategy could be easily controlled and is an alternative green approach for the production of graphene oxide and reduced graphene oxide.

Synergistic effects of a novel free-standing reduced graphene oxide film and surface coating fibronectin on morphology, adhesion and proliferation of mesenchymal stem cells

2015 ◽  
Vol 3 (21) ◽  
pp. 4338-4344 ◽  
Author(s):  
Lin Jin ◽  
Zhiping Zeng ◽  
Shreyas Kuddannaya ◽  
Dan Yue ◽  
Jingnan Bao ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Surface Coating ◽  
Synergistic Effects ◽  
Chemical Reduction ◽  
Nanofiber Membrane ◽  
Free Standing ◽  
Vacuum Filtration ◽  
Reduced Graphene

Fabrication of free-standing reduced graphene oxide (RGO) films by vacuum filtration of graphene oxide aqueous solution through a nanofiber membrane in combination with chemical reduction.

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.

Self-Assembled Reduced Graphene Oxide-TiO2 Thin Film for the Enhanced Photocatalytic Reduction of Cr(VI) Under Simulated Solar Irradiation

2019 ◽  
Vol 19 (6) ◽  
pp. 3376-3387 ◽  
Author(s):  
Hongyuan Shang ◽  
Min Ma ◽  
Fasheng Liu ◽  
Zhe Miao ◽  
Aiping Zhang
Keyword(s):  
Thin Film ◽  
Graphene Oxide ◽  
Visible Light ◽  
Reduced Graphene Oxide ◽  
Rate Constant ◽  
Solar Irradiation ◽  
Solar Light ◽  
X Ray ◽  
Simulated Solar Light ◽  
Reduced Graphene

In this study, reduced graphene oxide-TiO2 (RGO-TiO2) thin film was prepared by a simple self-assembly method at the gas/liquid interface. The as-prepared thin films were characterized by X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), UV-visible-diffuse reflectance spectroscopy (UV-vis-DRS) and X-ray photoelectron spectroscopy (XPS). Photocatalytic activities of TiO2 and RGO-TiO2 thin film were investigated via the reduction of Cr(VI) under simulated solar light and visible light (λ > 420 nm) irradiation. The results showed that the RGO-TiO2 thin film exhibited remarkably enhanced activity for photoreduction of Cr(VI) under simulated sunlight or visible light irradiation, with a reaction rate constant of 5.7 times greater than that of pure TiO2 thin film. The main reason for enhanced photocatalytic activity is that introduction of RGO can restrain the recombination of photogenerated electron–hole pairs and reduce the aggregation of TiO2 NPs. The effects of different reaction parameters such as irradiation time, irradiation source, pH values, catalyst dosage and initial Cr(VI) concentration were investigated in detail. The highest photoreduction efficiency of Cr(VI) was achieved and the reduction rate constant k was 0.0189 min−1 during the reduction of 0.5 mg L−1 of Cr(VI) with 10 cm2 RGO-TiO2 thin film at pH 2.0 and 293 K. Moreover, different scavengers were also added in the photoreduction of Cr(VI) system to identify the reactive species. Based on the results of the present study, a possible mechanism of photoreduction on RGO-TiO2 thin film under simulated solar light was proposed. Overall, this study provides a novel approach to efficiently photoreduction of Cr(VI) by RGO-TiO2 thin film.

Fabrication of N-doped Reduced Graphene Oxide/Ag3PO4 Nanocomposite with Excellent Photocatalytic Activity for the Degradation of Organic Pollutants

NANO ◽  
2017 ◽  
Vol 12 (01) ◽  
pp. 1750013 ◽  
Author(s):  
Longhai Feng ◽  
Lirong Kong ◽  
Zhenyuan Ji ◽  
Yi Wang ◽  
Xiaoping Shen ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photocatalytic Performance ◽  
Organic Pollutant ◽  
Charge Carriers ◽  
Simulated Solar Light ◽  
Solar Light Irradiation ◽  
Reduced Graphene ◽  
Excellent Photocatalytic Activity

An efficient N-doped reduced graphene oxide (N-RGO)/Ag3PO4 nanocomposite with enhanced photocatalytic activity has been prepared through a facile solution-based approach. Since N-RGO could offer more sites for the anchoring of Ag3PO4 nanoparticles, and effectively promote the charge carriers separation and transfer due to its high electrical conductivity, the photocatalytic activity of N-RGO/Ag3PO4 nanocomposite is much higher than bare Ag3PO4 and N-RGO in the degradation of phenol pollutant under simulated solar light irradiation. The mechanism for the photocatalytic process was also investigated. The excellent photocatalytic performance makes the N-RGO/Ag3PO4 nanocomposite a promising photocatalyst for organic pollutant treatment.

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

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
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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