@tut.ac.jp
Electrical and electronic information engineering
Toyohashi University of Technology
Scopus Publications
Rajesh Kumar, Sumanta Sahoo, Mona Elfiky, Raghvendra Pandey, Ram Manohar Yadav, Wai Kian Tan, Go Kawamura, Atsunori Matsuda, and Sally M. Youssry
Elsevier BV
El-Refaie Kenawy, Mohamed M. Azaam, Ahmed Z. Eldeep, Galal H. Ramzy, Ahmed I. Ali, and Sally M. Youssry
Springer Science and Business Media LLC
Sally M. Youssry, M. Abd Elkodous, Rajesh Kumar, Go Kawamura, Wai Kian Tan, and Atsunori Matsuda
Elsevier BV
Rajesh Kumar, Sally M. Youssry, Ednan Joanni, Sumanta Sahoo, Go Kawamura, and Atsunori Matsuda
Elsevier BV
Sally M. Youssry, I.S. El-Hallag, Rajesh Kumar, Go Kawamura, Wai Kian Tan, Atsunori Matsuda, and Marwa N. El-Nahass
Elsevier BV
Sally M. Youssry, M. Abd Elkodous, Go Kawamura, and Atsunori Matsuda
Royal Society of Chemistry (RSC)
Schematic diagram for the detailed steps of loading CDs-nanocomposite on nickel foam (NF) substrate to enhance the electrochemical performance of supercapacitor (SC) electrodes.
M. Abd Elkodous, Gharieb S. El-Sayyad, Sally M. Youssry, Hanady G. Nada, Mohamed Gobara, Mohamed A. Elsayed, Ahmed M. El-Khawaga, Go Kawamura, Wai Kian Tan, Ahmed I. El-Batal,et al.
Springer Science and Business Media LLC
Water scarcity is now a serious global issue resulting from population growth, water decrease, and pollution. Traditional wastewater treatment plants are insufficient and cannot meet the basic standards of water quality at reasonable cost or processing time. In this paper we report the preparation, characterization and multiple applications of an efficient photocatalytic nanocomposite (CoxNi1−xFe2O4; x = 0.9/SiO2/TiO2/C-dots) synthesized by a layer-by-layer method. Then, the photocatalytic capabilities of the synthesized nanocomposite were extensively-studied against aqueous solutions of chloramine-T trihydrate. In addition, reaction kinetics, degradation mechanism and various parameters affecting the photocatalytic efficiency (nanocomposite dose, chloramine-T initial concentration, and reaction pH) were analyzed in detail. Further, the antimicrobial activities of the prepared nanocomposite were tested and the effect of UV-activation on the antimicrobial abilities of the prepared nanocomposite was analyzed. Finally, a comparison between the antimicrobial abilities of the current nanocomposite and our previously-reported nanocomposite (CoxNi1−xFe2O4; x = 0.9/SiO2/TiO2) had been carried out. Our results revealed that the prepared nanocomposite possessed a high degree of crystallinity, confirmed by XRD, while UV–Vis. recorded an absorption peak at 299 nm. In addition, the prepared nanocomposite possessed BET-surface area of (28.29 ± 0.19 m2/g) with narrow pore size distribution. Moreover, it had semi-spherical morphology, high-purity and an average particle size of (19.0 nm). The photocatalytic degradation efficiency was inversely-proportional to chloramine-T initial concentration and directly proportional to the photocatalyst dose. In addition, basic medium (pH 9) was the best suited for chloramine-T degradation. Moreover, UV-irradiation improved the antimicrobial abilities of the prepared nanocomposite against E. coli, B. cereus, and C. tropicalis after 60 min. The observed antimicrobial abilities (high ZOI, low MIC and more efficient antibiofilm capabilities) were unique compared to our previously-reported nanocomposite. Our work offers significant insights into more efficient water treatment and fosters the ongoing efforts looking at how pollutants degrade the water supply and the disinfection of water-borne pathogenic microorganisms.
Rajesh Kumar, Sally M. Youssry, Mohamed M. Abdel-Galeil, and Atsunori Matsuda
Springer Science and Business Media LLC
In this article, we have demonstrated single-step as well as scalable synthesis of zinc oxide nanoparticles (ZnO NPs) supported on highly thin/transparent reduced graphene oxide (rGO) nanocomposite (ZnO@rGO) via direct microwave irradiation using decomposition of zinc acetate dihydrate (Zn(CH3CO2)2·2H2O) along with reduction of graphite oxide. The surface microstructure of prepared ZnO@rGO nanocomposite was analyzed by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, Raman spectroscopy, and X-ray photo electron spectroscopy. Different characterization analysis indicates that the ZnO NPs in the nanocomposite were dispersed on the surfaces of rGO nanosheets (NSs). Raman spectra reveal the structural defects level of rGO NSs was 0.78, while it was increased to 1.66 for ZnO@rGO nanocomposites. The synthesized ZnO@rGO nanocomposite exhibits specific capacitance of 102.4 F/g at the scan rate of 30 mV/s and shows good cyclic stability of 82.5% for 3000 cycles at high scan rate 100 mV/s.
Rajesh Kumar, Sally M. Youssry, Han Min Soe, Mohamed M. Abdel-Galeil, Go Kawamura, and Atsunori Matsuda
Elsevier BV
Abstract Honeycomb-like open edges reduced graphene oxide nanosheets (HOrGO NSs) filled with transition metal oxides (TMOs) as NiO/Co3O4 nanoparticles (NPs) has been synthesized by a simple and cost-effective microwave irradiation method. The microwave irradiation assisted synthesized HOrGO filled with NiO/Co3O4 NPs (HOrGO/TMOs) hybrids exhibits high specific capacitance with improved cycling stability as excellent electrode materials for supercapacitors (SCs). The HOrGO NSs contains high surface area (~570 m2 g−1) due to highly exfoliated nanostructure comprising open edges enriched morphology. In HOrGO/TMOs hybrids, the several micron-sized (~100 μm) open edges of HOrGO NSs holds the NiO/Co3O4 NPs with finely separated thin few-layer graphene NSs. The structural/ morphological analysis of synthesized HOrGO NSs and HOrGO/TMOs hybrids were extensively characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Raman spectra, thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller (BET) surface area. The HOrGO/TMOs hybrids deliver high specific capacitance of 910 F g−1 and high robust cycling stability with capacitance retention as 89.9% after continuous 2000 cycles. The proposed mechanism explain the microwave irradiation assisted formation of HOrGO/TMOs hybrids and provides a general and low-cost approach to synthesized high quality graphene hybrids materials for SCs application.
Sally M. Youssry, Marwa N. El-Nahass, Rajesh Kumar, I.S. El-Hallag, Wai Kian Tan, and Atsunori Matsuda
Elsevier BV
Abstract In this work we report the synthesis of electrochemically deposited Ni(OH)2 nanoparticles on the surface of in-situ electrochemically reduced graphene oxide nanosheets (ErGO NSs) supported on 3D networked nickel foam (NF) to form Ni(OH)2-ErGO@NF as electrode materials for supercapacitor (SCs) application. The adopted three-electrode electrochemical system via a two-step process for the synthesis of Ni(OH)2-ErGO@NF was fast and cost effective. First, 2D nanosheets of ErGO were deposited on NF by potential square wave technique. Second, Ni(OH)2 nanoparticles were deposited on the surface of 2D nanosheets ErGO by potentiostat. The electrochemical behavior of the Ni(OH)2-ErGO@NF electrode was measured in 1 M KOH and revealed an impressive supercapacitive performance, with high specific capacitance of 3138 F/g at scan rate 20 mV/s. The synthesized Ni(OH)2-ErGO@NF exhibited excellent cyclic stability, with capacitance retention of 88.6% after 3000 cycles at a scan rate 50 mV/s. The enhanced electrochemical performance of SCs was attributed to the superior conductivity of ErGO NSs, which facilitated the transfer of charges and the diffusion of KOH electrolyte, making it is a promising candidate for SCs electrodes. This synthesis provides an appropriate approach for preparing other kinds of metal hydroxides with rGO for improved SCs electrode performance.
Sally M. Youssry, I.S. El-Hallag, Rajesh Kumar, Go Kawamura, Atsunori Matsuda, and Marwa N. El-Nahass
Elsevier BV
Abstract Here we report synthesis of mesoporous structure containing two different phases of Co(OH)2 by different routes. The β-Co(OH)2 film and mesoporous α-Co(OH)2 powder synthesized using electrochemical deposition and chemical reduction methods, respectively using lyotropic liquid crystal (LLC) templates. These synthesized mesoporous β-Co(OH)2 film and α-Co(OH)2 powder were utilized as electrode materials for supercapacitors (SCs)application. The surface structure/morphology of these synthesized materials were analyzed by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscope (TEM), wide/low-angle X-ray diffraction (XRD) and Raman spectroscopy. The as-synthesized mesoporous β-Co(OH)2 film and mesoporous α-Co(OH)2 powder contain particles size in the range of 270–300 nm and 70–90 nm, respectively. For application as electrode in SCs, mesoporous β-Co(OH)2 film on FTO reveals enhanced electrochemical performance as compared to mesoporous α-Co(OH)2 powder in 1 M KOH electrolyte as high specific capacitance with a significant tremendous long-term cyclic stability. The specific capacitance of mesoporous β-Co(OH)2 film was 605 F/g at scan rate 10 mV/s and superior cyclic stability as capacitance retention of 94.4% over 2000 cycles. Uniform and homogeneous Co(OH)2 nanoparticles inside film enhance the electrochemical performance for SCs due to easy penetration and access of KOH electrolyte inside mesoporous structure. The reported synthesis method provides a suitable and fast approach to synthesize other kind of metal hydroxide mesoporous structure for electrode purpose for different energy storage devices.
Rajesh Kumar, Sally M. Youssry, Kyaw Zay Ya, Wai Kian Tan, Go Kawamura, and Atsunori Matsuda
Elsevier BV
Abstract Tailoring binary transition-metal oxide nanoparticles with two-dimensional novel carbon nanomaterials has become a desired way to increase their electrochemical performance for energy storage application. In this work, binary metal oxide (Mn3O4-Fe2O3/Fe3O4 nanoparticles) anchored reduced graphene oxide nanosheets (rGO NSs) have been successfully synthesized by a simple and low-cost microwave-assisted synthesis for supercapacitor (SCs) electrode applications. As characterized by scanning electron microscopy and transmission electron microscopy, Mn3O4-Fe2O3/Fe3O4 nanoparticles with size of
Ibrahim S. El-Hallag, Marwa N. El-Nahass, Sally M. Youssry, Rajesh Kumar, Mohamed M. Abdel-Galeil, and Atsunori Matsuda
Elsevier BV
Abstract We have reported fast and simple synthesis of electrochemically reduced graphene oxide nanosheets (ErGO NSs)-embedded-palladium nanoparticles (Pd-E-ErGO) hybrids on nickel (Ni) sheet for high performance electrochemical supercapacitors (SCs) electrode. The Pd-E-ErGO hybrids material was successfully prepared by facile and one-pot in-situ electrochemical reduction and deposition using water as solvent in which palladium nanoparticles (Pd NPs) were uniformly embedded inside 2D-nanosheets of ErGO. During electrochemical reduction, graphene oxide nanosheets were reduced into ErGO NSs and PdCl2 ionized to form Pd2+ which attracted to the negative oxygen containing functional groups of ErGO NSs then reduced to form Pd NPs which embedded completely between ErGO NSs structure. The surface/structural morphology of Pd-E-ErGO hybrids was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDS) and Raman spectroscopy. The proportions of elements present in hybrids were determined by EDS and thermogravimetric analysis (TGA). As an application, the synthesized Pd-E-ErGO hybrids revealed enhanced electrochemical performance as high specific capacitance with excellent cycling stability which was very significant for electrochemical SCs. The Pd-E-ErGO hybrids electrode fulfills an approving specific capacitance value of 1524.7 F/g at a scan rate of 20 mV/s and improved cycling stability of 92.1% capacitance retention after 2000 cycles in the three-electrode setup. The electrochemical synthesis of Pd-embedded-graphene derivatives structure as well as improved electrochemical performance for SCs opens up a new idea to prepare electrode materials.