scholarly journals Sensitivity Enhancement of Pb(II) Ion Detection in Rivers Using SPR-Based Ag Metallic Layer Coated with Chitosan–Graphene Oxide Nanocomposite

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5159 ◽  
Author(s):  
Nurul Fariha Lokman ◽  
Nur Hidayah Azeman ◽  
Fatihah Suja ◽  
Norhana Arsad ◽  
Ahmad Ashrif A Bakar
Keyword(s):  
Thin Film ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Film Surface ◽  
Detection Accuracy ◽  
Ion Detection ◽  
Force Microscopy ◽  
Adsorption Sites ◽  
Thin Film Surface ◽  
Atomic Force

The detection of Pb(II) ions in a river using the surface plasmon resonance (SPR)-based silver (Ag) thin film technique was successfully developed. Chitosan–graphene oxide (CS-GO) was coated on top of the Ag thin film surface and acted as the active sensing layer for Pb(II) ion detection. CS-GO was synthesized and characterized, and the physicochemical properties of this material were studied prior to integration with the SPR. In X-ray photoelectron spectroscopy (XPS), the appearance of the C=O, C–O, and O–H functional groups at 531.2 eV and 532.5 eV, respectively, confirms the success of CS-GO nanocomposite synthesis. A higher surface roughness of 31.04 nm was observed under atomic force microscopy (AFM) analysis for Ag/CS-GO thin film. The enhancement in thin film roughness indicates that more adsorption sites are available for Pb(II) ion binding. The SPR performance shows a good sensor sensitivity for Ag/CS-GO with 1.38° ppm−1 ranging from 0.01 to 5.00 ppm of standard Pb(II) solutions. At lower concentrations, a better detection accuracy was shown by SPR using Ag/CS-GO thin film compared to Ag/CS thin film. The SPR performance using Ag/CS-GO thin film was further evaluated with real water samples collected from rivers. The results are in agreement with those of standard Pb(II) ion solution, which were obtained at incidence angles of 80.00° and 81.11° for local and foreign rivers, respectively.

scholarly journals Photocatalytic reduction of graphene oxide with cuprous oxide film under UV-vis irradiation

2020 ◽  
Vol 59 (1) ◽  
pp. 207-214 ◽  
Author(s):  
Yao Wang ◽  
Jianqing Feng ◽  
Lihua Jin ◽  
Chengshan Li
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Photocatalytic Reduction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Reduced Graphene ◽  
Reduction Efficiency ◽  
Metal Organic ◽  
Reduction Effect

AbstractWe have grown Cu2O films by different routes including self-oxidation and metal-organic deposition (MOD). The reduction efficiency of Cu2O films on graphene oxide (GO) synthesized by modified Hummer’s method has been studied. Surface morphology and chemical state of as-prepared Cu2O film and GO sheets reduced at different conditions have also been investigated using atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). Results show that self-oxidation Cu2O film is more effective on phtocatalytic reduction of GO than MOD-Cu2O film. Moreover, reduction effect of self-oxidation Cu2O film to GO is comparable to that of environmental-friendly reducing agent of vitamin C. The present results offer a potentially eco-friendly and low-cost approach for the manufacture of reduced graphene oxide (RGO) by photocatalytic reduction.

Characterization of X-ray irradiated graphene oxide coatings using X-ray diffraction, X-ray photoelectron spectroscopy, and atomic force microscopy

2013 ◽  
Vol 28 (2) ◽  
pp. 68-71 ◽  
Author(s):  
Thomas N. Blanton ◽  
Debasis Majumdar
Keyword(s):  
Atomic Force Microscopy ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
High Energy ◽  
X Ray Diffraction ◽  
Carbon Phase ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After

In an effort to study an alternative approach to make graphene from graphene oxide (GO), exposure of GO to high-energy X-ray radiation has been performed. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) have been used to characterize GO before and after irradiation. Results indicate that GO exposed to high-energy radiation is converted to an amorphous carbon phase that is conductive.

scholarly journals Structural, chemical and magnetic properties of nickel vertical posts obtained by glancing angle deposition technique

2017 ◽  
Vol 49 (1) ◽  
pp. 73-79
Author(s):  
Jelena Potocnik ◽  
Milos Nenadovic ◽  
Bojan Jokic ◽  
Maja Popovic ◽  
Zlatko Rakocevic
Keyword(s):  
Thin Film ◽  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Glancing Angle Deposition ◽  
Deposition Technique ◽  
Force Microscopy ◽  
Atomic Force ◽  
Glancing Angle ◽  
Magneto Optical Kerr Effect ◽  
Angle Deposition

In this work, Glancing Angle Deposition technique was used for obtaining nanostructured nickel thin film with vertical posts on glass substrate which was positioned 75 degrees with respect to the substrate normal and rotated with a suitable constant speed. The obtained nickel thin film was characterized by Scanning Electron Microscopy, Atomic Force Microscopy and X-ray Photoelectron Spectroscopy. It was found that the deposited thin film consists of 94.0 at.% of nickel. Magnetic properties of the deposited thin film were determined by Magneto-Optical Kerr Effect Microscopy. According to the obtained coercivity values, it can be concluded that the nickel thin film shows uniaxial magnetic anisotropy.

scholarly journals Polystyrene as Graphene Film and 3D Graphene Sponge Precursor

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 101 ◽  
Author(s):  
Alejandra Rendón-Patiño ◽  
Jinan Niu ◽  
Antonio Doménech-Carbó ◽  
Hermenegildo García ◽  
Ana Primo
Keyword(s):  
Thin Film ◽  
Atomic Force Microscopy ◽  
Photoelectron Spectroscopy ◽  
Graphene Film ◽  
Visible Absorption ◽  
X Ray ◽  
3D Graphene ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Sponge

Polystyrene as a thin film on arbitrary substrates or pellets form defective graphene/graphitic films or powders that can be dispersed in water and organic solvents. The materials were characterized by visible absorption, Raman and X-ray photoelectron spectroscopy, electron and atomic force microscopy, and electrochemistry. Raman spectra of these materials showed the presence of the expected 2D, G, and D peaks at 2750, 1590, and 1350 cm−1, respectively. The relative intensity of the G versus the D peak was taken as a quantitative indicator of the density of defects in the G layer.

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