Dang Du Nguyen

Bio: Dang Du Nguyen is an academic researcher from Sungkyunkwan University. The author has contributed to research in topics: Graphene & Graphene oxide paper. The author has an hindex of 1, co-authored 2 publications receiving 17 citations.

Electrical Measurements of Thermally Reduced Graphene Oxide Powders under Pressure

Abstract: Graphene powders obtained via the reduction of graphene oxide flakes have been widely used in various applications as they can be synthesized in large quantities with outstanding properties. The electrical conductivity of graphene powders is critical for their uses in fabricating high-performance devices or materials. Here, we investigated the bulk electrical conductivity of reduced graphene oxide (rGO) powders depending on the applied pressure and additional thermal annealing. The electrical conductivity of the rGO powders was correlated with the change in the carbon-to-oxygen ratio via additional thermal reduction. Furthermore, the effect of the morphology of the rGO powders was studied through electromechanical measurements. This study provides a reliable method for the electromechanical characterization of rGO powders and a better understanding of the electrical conductivity of graphene-based materials.

Tunable Interlayer Interactions in Reduced Graphene Oxide Paper.

Abstract: Free-standing graphene-based paper-like materials have garnered significant interest for various applications because of their tunable physical and chemical properties, along with unique multilayered structures. Because of the layered configuration of graphene paper, characterization of the interactions between graphene sheets is critical for understanding its fundamental properties and applications. We investigate the interlayer cohesion energies in graphene papers using the mode I fracture concept with double cantilever beam specimens. Mechanical separation along the middle of the graphene paper thickness enables the evaluation of interlayer bonding strength in the paper. Starting from graphene oxide paper, the chemical reduction using hydroiodic acid tunes the interlayer cohesion energy from 11.30 ± 0.25 to 4.78 ± 0.18 J/m2 as the reduction time increases. The interlayer cohesion energy is correlated with the oxygen content, interlayer spacing, and electrical conductivity of graphene papers. This work provides a fundamental characterization of the interlayer cohesion energy of graphene paper and establishes the potential for tunability of the interlayer interactions in graphene paper.

Interlayer Separation in Graphene Paper Comprising Electrochemically Exfoliated Graphene

Abstract: The emergence of graphene paper comprising well-stacked graphene flakes has promoted the application of graphene-based materials in diverse fields such as energy storage devices, membrane desalination, and actuators. The fundamental properties of graphene paper such as mechanical, electrical, and thermal properties are critical to the design and fabrication of paper-based devices. In this study, the interlayer interactions in graphene paper were investigated by double cantilever beam (DCB) fracture tests. Graphene papers fabricated by flow-directed stacking of electrochemically exfoliated few-layer graphene flakes were mechanically separated into two parts, which generated force-displacement responses of the DCB sample. The analysis based on fracture mechanics revealed that the interlayer separation energy of the graphene paper was 9.83 ± 0.06 J/m2. The results provided a fundamental understanding of the interfacial properties of graphene papers, which will be useful for developing paper-based devices with mechanical integrity.

Green synthesis, characterization and potential application of reduced graphene oxide

Abstract: This study investigates the structure and composition of graphene produced by thermal reduction of graphene oxide (GO) at various temperatures, for short time (5 min). The influence of reduction temperature on the structural properties of graphene was studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier Transform Infrared (FTIR) spectroscopy, UV–Vis spectroscopy, thermogravimetric analysis (TGA), Raman and X-ray photoelectron spectroscopy (XPS). We demonstrated that by controlling the temperature in the annealing process, we can design materials with desired composition to meet the necessities for future or existing applications. The synthesized materials proved to have great potential in the atenolol adsorption from wastewater at room temperature (61% removal efficiency after 30 min).

Graphene oxide for photonics, electronics and optoelectronics

Abstract: Graphene oxide (GO) was initially developed to emulate graphene, but it was soon recognized as a functional material in its own right, addressing an application space that is not accessible to graphene and other carbon materials. Over the past decade, research on GO has made tremendous advances in material synthesis and property tailoring. These, in turn, have led to rapid progress in GO-based photonics, electronics and optoelectronics, paving the way for technological breakthroughs with exceptional performance. In this Review, we provide an overview of the optical, electrical and optoelectronic properties of GO and reduced GO on the basis of their chemical structures and fabrication approaches, together with their applications in key technologies such as solar energy harvesting, energy storage, medical diagnosis, image display and optical communications. We also discuss the challenges of this field, together with exciting opportunities for future technological advances. As the most common derivative of graphene, graphene oxide has emerged as a new frontier material with tremendous applications to photonics, electronics and optoelectronics in the past decade. This Review highlights the state of the art and future prospects for this fast-growing field.

Graphene oxide: new opportunities for optoelectronic, electronic and photonic chips

Abstract: Graphene oxide (GO) was initially developed to emulate graphene, but it was soon recognized as a functional material in its own right, addressing an application space that is not accessible to graphene and other carbon materials. Over the past decade, research on GO has made tremendous advances in material synthesis and property tailoring. These, in turn, have led to rapid progress in GO-based photonics, electronics and optoelectronics, paving the way for technological breakthroughs with exceptional performance. In this Review, we provide an overview of the optical, electrical and optoelectronic properties of GO and reduced GO on the basis of their chemical structures and fabrication approaches, together with their applications in key technologies such as solar energy harvesting, energy storage, medical diagnosis, image display and optical communications. We also discuss the challenges of this field, together with exciting opportunities for future technological advances. As the most common derivative of graphene, graphene oxide has emerged as a new frontier material with tremendous applications to photonics, electronics and optoelectronics in the past decade. This Review highlights the state of the art and future prospects for this fast-growing field.